R Quality Assurance Techniques - r

Could you provide some insight into the techniques that you use to ensure the quality of your solutions. For example, sometimes, I like to test my result using stopifnot() to ensure I'm not receiving ridiculous results. Are there any other techniques or functions that you use in data processing to ensure that you're receiving the solution you meant to?
Note: I realize that this is a broad question and perhaps a candidate for community wiki or even closure, but rather than voting to close, perhaps assist me by adding comments to direct the conversation.

Just a few things that come to mind (in random order)
This page has very interesting link for debugging in R (ok this is during production, but still related to your issue I think)
You can use exceptions, as explained in this discussions (and links therein)
You can write tests with known results (both for success and failure) and see that they actually do what they are supposed to do. Be sure to pass some weird data to the functions and see how they behave in a "not-so-normal" situation.
Don't just rely on automated tests: give your functions to a fairly computer illiterate person at work (not enough that he/she can't use R though!) and let him/her do some beta tests. You'll be amazed at the quantity of errors he/she will come up with!!! :)

Quality in software engineering is quite a massive area, and most of it applies to code written in R as much as code written in Cobol or C#, so my first answer would be 'it depends'.
For me, I come from the Pharmaceutical Industry, where what we do is regulated by government agencies like the FDA and the MHRA. For us, Quality is something we think about throughout the process so I would list the following as visible artifacts of quality;
We have a software development process, that's written down and repeatable (traditionally in this kind of industry this is a waterfall style, but more and more agile / prototyping style methodologies are being used)
We have a system that ensures every person involved knows what they should be doing (job descriptions) and is suitably qualified to do that job (training)
We start by defining what is required in some way, hopefully in some way that can be tested
We have some way of documenting our development process, where we've been and how (a combination of good documentation and Source Control)
We do testing wherever possible, and as early as possible (so, automated if possible)
We have people who are responsible for overseeing Quality, who are separate from people who are doing to prevent conflicts
We control the software environment that is used for development, testing and production (read; change control)
We control and manage software once it is in use, tracking issues and managing them (Issue Tracking)
We keep records, so that even if every person involved went under a bus / won the lottery the new people could still defend and prove everything above to a government inspector.
However, that's a big list, and I imagine their are lots of industries that don't do all of them (finance, education) and probably some who do more (building nuclear reactors, saving lives, NASA).
More specifically to what i assume you're getting at, before you code you should be able to define some specific starting input's and the answers you should get out, and I recommend you use something like RUnit or Testthat to build these in.

Related

Regarding Automation Approach

I am supposed to automate an application which is developed in PowerBuilder. In order to test this Application we are using Rational Robot as a functional testing tool. We expect at least 40 -50% of change control in the Application for each release. Release trends are scheduled at least 3 times in a year.
The product has different setup for each client. Accordingly scenario has been derived. Although if is there any change occurs, it would be in functional feature and also in interface. Pointing to that, need to proceed with automation. Identified few areas which are stabilized (i.e., where no major changes occurs) to automate. Will that be feasible for proceeding with Automation?
Could you please suggest me how to go about on this?
I've seen the answer to your last question involve a consultant spending two days interviewing the development team, then three days developing a report. And, in some cases, I'd say the report was preliminary, introductory, and rushed. However, let me throw out a few ideas that may help manage expectations on your team.
Testing automation is great for checking for regressions in functionality that allegedly isn't being touched. Things like framework changes or database changes can cause untouched code to crash. For risk-averse environments (e.g. banking, pharmaceutical prescriptions), the investment in automation is well worth the effort.
However, what I've seen often is an underestimation of the effort. To really test all the functionality in a unit (let's say a window, for example), you need to review the specifications, design tests that test each functional point, plan your data (what is the data going into the window, how will you make sure this data is as expected when you start the test each time, what is the data when you've finished your tests, how will you ensure the data, including non-visible data, is correct), then script and debug all your tests. I'm not sure what professional testers say (I'm a developer by trade, but have taken a course in an automated testing tool), but if you aren't planning for the same amount of effort to be expended on developing the automation tests as you're spending on application development for the same functionality, I think you'll quickly become frustrated. Add to that the changing functionality means changing testing scripts, and automated testing can become a significant cost. (So, tell your manager that automated testing doesn't mean you push a button and things get tested. < grin > )
That's not to say that you can't expend less effort on testing and get some results, but you get what you pay for. Having a script that opens and closes all the windows in the app provides some value, but it won't tell you that a new behaviour implemented in the framework is being overridden on window X, or that a database change has screwed up the sequencing of items in a drop down DataWindow, or a report completion time goes from five seconds to five hours. However, again, don't underestimate the effort. This is a new tool with a new language and idiosyncrasies that need to be figured out and mastered.
Automated testing can be a great investment. If the cost of failure is significant, like a badly prescribed drug causing a death, then the investment is worth it. However, for cases where there is a high turn over of functionality (like I think you're describing) and the consequences of a failure is less critical, you might want to consider comparing the cost/benefit of testing automation with additional manual testing resources.
Good luck,
Terry
Adding on to what #Terry said: It sounds like you are both new to automation in general and to Rational Robot in particular.
One thing to keep in mind is that test automation is software development and needs to be treated as such. That means you need personnel dedicated to the automation effort who are solid programmers and have expertise in the tool being used (Robot in this case).
If your team does not have the general programming/automation skills and the specific Robot skills, you are going to need to hire that personnel or get existing staff trained in those skill sets.

What are your feelings on functional specs? And Software design? [closed]

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Does the functional spec help or hinder your expectations? Do programmers who practice the waterfall methodology, are they open to functional specs? I'm a web designer/developer working with a team of 5 programmers and would like to write a functional spec to explain what we need, so that when I begin my work - I know we are working towards the same goal.
I won't start any freelance project until I've got a design spec and functional spec written up and signed off. There's too much room for rogue clients to nickel and dime you to death if you don't have it. The functional spec allows you to stay on target/focused and gives you a natural check list to work to.
If there's no functional spec then you get all the "what ifs" starting to creep in and developers thinking - you know, this would be useful, and it'll only take me an hour. Sure an hour to code the prototype and get it basically working - plus the day to design all the tests and make sure all test cases are covered, then another couple of days to iron out all the bugs, then time to write the documentation. There's far too much room for what seems like a trivial addition to be inserted when there's no spec. You've no doubt heard of the infamous "scope creep". There's also far too much room for clients to say "that's not what I wanted..." when you deliver it and try and wriggle out of paying you.
If you've got the design spec and the functional spec written up ahead of the development and both you and the client have signed off that your understanding of not only the basic details but all the nuances of the language used is one and the same - only then can the real work begin.
There are a couple of anecdotes out there the first is quite true, while the other is a common misconception:
Software development is only 15% about the code, the rest is resource/people management.
It takes 20% of the time to complete the first 80% of the project and the remaining 80% of the time to complete the last 20%.
The misconception is that a working prototype is 80% of the way there - don't be fooled, it is not. So it's easy for a client to say "what's taking so long, I thought you were almost done!" and then quibble that they're paying too much for something that should've been finished months ago. Some of the design methodologies out there really lend themselves well to this popular misconception. The waterfall design methodology is one of them if it's not used correctly.
My view is make sure your understanding is the same, both sign off. Set milestones and make the client very aware at the outset that prototypes are a long way from the completion of the project and set expectations right from the outset as to what those milestones are and when the client can expect to see them delivered.
For project managers of development teams documentation and expectations are everything. You can't live without it, it's the only form of recourse you have against "That's not what I said" or "That's not what I meant" and ergo "I'm not paying you".
I learned from a lot of mistakes made by far more qualified developers than me and saw what it did to them. The two most important documents for your project are the design spec and the functional spec. Don't leave home without them or it can [or most likely will] come back and bite you in the ass.
Addendum re: User Stories:
An additional note about user stories is that they're great for what they are. They should be included in your functional specification but shouldn't be your functional specification.
A user story only describes a single task. It is very lightweight and doesn't contain excessive detail. As the common recommendations go, it should fit on a 3x5 card...if you as a project manager handed me a 3x5 card and told me to write a piece of software based on what I read, no doubt it would be handed to the user at the end and they'd tell the project manager that's not what they wanted.
You need a far greater level of detail in a functional spec. It shouldn't be limited to basic workflows. A functional spec is a whole bunch of user stories along with notes on interpretation of those user stories, improvements that can be made to them, common tasks that can be combined to improve efficiency. The list goes on.
So user stories are a good beginning, but they're not a replacement for a functional spec, they're bullet points in a functional spec.
I work with mostly the Waterfall model, and solely with functional specs. When working on my own (where I can set my own model and program any way I want) I start by writing up functional specs and then implementing them. It gives me a much better idea of the size and scope of the work, helps me estimate the time involved, and helps ensure that I don't miss anything.
Also, you can pass this document to:
Users so that they can make their requirements clear
Developers to create the functionality
Testers to make sure they are testing the right thing
Architects so that they can analyze the requirements
Using functional requirements over user stories is a matter of preference and the scope of the project. If you have a small user base, then you may be able to get away with user stories (which outline various event sequences the user might do), but for larger projects, you should use functional requirements as they have more detail and lead to fewer misunderstandings. Think of them as a means of communication with all people involved in the project.
Frankly, the Functional Specifications should already be part of your Big-M (Waterfall) methodology. Your functional specification is WHAT you are going to build; not necessarily how you are going to build it (which would be your detailed design/specification and the next step in the waterfall).
If you haven't written one yet, stop what you are doing and write one. You are just waste time if you do otherwise. You can start here with Joel's article.
It took me more than 10 years to get it beat into my head to write a functional spec before doing any code. Now I will write one for anything taking more than a day to write. The level of detail, and level of assumptions should be as much as needed to clearly define what needs to be done and communicate it to others (or remind yourself), anything beyond that is a waste.
Others prefer User Stories ... which is fine too, as long as you do some kind of planning.
Another way to accomplish this is using user stories
I find well-written functional specs very useful. A well organized functional specification can also help organize your tests (many-to-many mapping from individual requirements to test cases).
<p style="tongue: in-cheek">They also prove useful for finger-pointing in larger organizations (The requirements were inaccurate! The implementation didn't follow the requirement! QA didn't properly test this requirement! etc.)</p>
I'll second Codeslave's reference to Painless Functional Specification. It's a good series of articles on specifications. See also this Stackoverflow post for a discussion on what content to put into functional specs.
I've done a few large projects, including one with some hundereds of person-years of total effort. As a project team gets larger the number of informal communication channels goes up with a quadratic upper bound. Without a spec this informal communication mechanism is the only way things can get communicated. With a spec, the communication channels approach a hub-and-spokes, making the growth more like a linear function of the project team size.
A spec is really the only scalable way to to get the team 'singing off the same hymn sheet'. There should be some review and negotiation about the spec, but ultimately someone has to take ownership of this to avoid the project becoming a free-for-all.
I think they're a lovely idea, and should be tried.
Just a few comments on some of the answers here...
First of all, I do believe that a good spec document is important for any moderatly complex requirement (and definitly for highly complex ones). But make sure it is a good spec i.e. don't just state the obvious (like one poster already mentioned) but also don't leave out those parts that may seem trivial to you (or even the developers) since you might have more knowledge of that part of the system than some others involved (e.g. testers or documenters) which will appreciate the otherwise "missing bits".
And if your spec is good, it will get read - in my experience (and I've written and read lots of specs over the last years) it's the bad specs that get dumped and the good ones that get followed.
Concerning user stories (or sometimes also called use cases): I think these are important to get an idea of the scenario, but they usually can't replace the details (e.g. screen mockups, how where and if a feature is configurable, data model, migration issues etc.) so you'll probably need both for more complex requirements.
In my experience, functional specs have a fine line between not saying enough and saying too much.
If they don't say enough, then they leave areas open to misunderstanding.
If they say too much, they don't leave enough "wiggle room" to improve the solution.
And they should always be open to a process of revision.
It depends on the functional specification. I've had functional specifications where the writer knew the system inside and out, and wrote the specification as such, and I've had other writers write it with just what they expected to see as a user.
With the former, it's easier because I know exactly what I need to write and where I need to write it, but it limits how easily I can refactor the existing code, since estimates took into account just this feature, and not refactoring existing code that it touches.
With the latter, I have freedom to refactor (so long as end functionality is the same), but if it's a system I'm unfamiliar with, the time estimate is harder to make.
Overall, I love functional specifications -- I also like to remind people that they're written on paper that bends, and as such, should be flexible.
Whether you call them functional specs, business requirements, or user stories, they are all very beneficial to the development process.
The issue with them comes when they are chiseled in stone and used as a device to pass blame around when the system utimately doesn't fit with the user's real needs. I prefer to use the functionals or requirements as a starting point for an iterative process not as the bible for exactly how the system will look when it is complete. Things change, and users typically don't have an understanding of what they want until they have something (a working prototype possibly) in their hands that they can work with instead of conceptualizing on a piece of paper how it will function in the real world. The most successful projects I've implemented were ones where the development team and the users were closely aligned and were able to rapidly turn around changes instead of holding people to what they wanted on a piece of paper six months ago.
Of course this process wouldn't work if you were in a fixed-bid type of situation as one of the earlier answers pointed out.
One interesting substitute for a func spec or user stories that I have seen advocated is to write a user manual for the software first.
Even if this is only notional (i.e. if you do not intend to ship any manual - which you probably shouldn't as nobody will read it), it can be a useful and reasonably lightweight way to reach a common understanding of what the software will do and look like. And it forces you to do the design up front.
I've found that even if you write Functional Specs a lot of the detail is sometimes lost on the person you are trying to address. Now if a Functional Spec is written along with some kind of UI mockup, that makes a huge difference. UI mockups not only show the user what you are envisioning, it also triggers users into remembering things they wouldn't have thought off in the first place.
I have seen and written many specs, some were very good, most weren't. The main thing that they all had in common is that they were never followed. They all had cobwebs on them by the 3rd day of coding.
Write the spec if you want, the best time to do it is at the end of the project. It will be useless for developers to follow but it will at least be an accurate representation of what was done (I know- not really a spec). But don't expect the spec to get the code written for you. That is the real job. If you don't know what to write talk to your stakeholders and users and get some good user stories and then get on with it.

How to Convince Programming Team to Let Go of Old Ways?

This is more of a business-oriented programming question that I can't seem to figure out how to resolve. I work with a team of programmers who have been working with BASIC for over 20 years. I was brought in to help write the same software in .NET, only with updates and modern practices. The problem is that I can't seem to get any of the other 3 team members(all BASIC programmers, though one does .NET now as well) to understand how to correctly do a relational database. Here's the thing they won't understand:
We basically have a transaction that keeps track of a customer's tag information. We need to be able to track current transactions and past transactions. In the old system, a flat-file database was used that had one table that contained records with the basic current transaction of the customer, and another transaction that contained all the previous transactions of the customer along with important money information. To prevent redundancy, they would overwrite the current transaction with the history transactions-(the history file was updated first, then the current one.) It's totally unneccessary since you only need one transaction table, but my supervisor or any of my other two co-workers can't seem to understand this. How exactly can I convince them to see the light so that we won't have to do ridiculous amounts of work and end up hitting the datatabse too many times? Thanks for the input!
Firstly I must admit it's not absolutely clear to me from your description what the data structures and logic flows in the existing structures actually are. This does imply to me that perhaps you are not making yourself clear to your co-workers either, so one of your priorities must be to be able explain, either verbally or preferably in writing and diagrams, the current situation and the proposed replacement. Please take this as an observation rather than any criticism of your question.
Secondly I do find it quite remarkable that programmers of 20 years experience do not understand relational databases and transactions. Flat file coding went out of the mainstream a very long time ago - I first handled relational databases in a commercial setting back in 1988 and they were pretty commonplace by the mid-90s. What sector and product type are you working on? It sounds possible to me that you might be dealing with some sort of embedded or otherwise 'unusual' system, in which case you do need to make sure that you don't have some sort of communication issue and you're overlooking a large elephant that hasn't been pointed out to you - you wouldn't be the first 'consultant' brought into a team who has been set up in some manner by not being fed the appropriate information. That said such archaic shops do still exist - one of my current clients systems interfaces to a flat-file based system coded in COBOL, and yes, it is hell to manage ;-)
Finally, if you are completely sure of your ground and you are faced with a team who won't take on board your recommendations - and demonstration code is a good idea if you can spare the time -then you'll probably have to accept the decision gracefully and move one. Myself in this position I would attempt to abstract out the issue - can the database updates be moved into stored procedures for example so the code to update both tables is in the SP and can be modified at a later date to move to your schema without a corresponding application change? Make sure your arguments are well documented and recorded so you can revisit them later should the opportunity arise.
You will not be the first coder who's had to implement a sub-optimal solution because of office politics - use it as a learning experience for your own personal development about handling such situations and commiserate yourself with the thought you'll get paid for the additional work. Often the deciding factor in such arguments is not the logic, but the 'weight of reputation' you yourself bring to the table - it sounds like having been brought in you don't have much of that sort of leverage with your team, so you may have to work on gaining a reputation by exceling at implementing what they do agree to do before you have sufficient reputation in subsequent cases - you need to be modded up first!
Sometimes you can't.
If you read some XP books, they often say that one of your biggest hurdles will be convincing your team to abandon what they have always done.
Generally they will recommend letting people who can't adapt go to other projects (Or just letting them go).
Code reviews might help in your case. Mandatory code reviews of every line of code is not unheard of.
Sometime the best argument is an example. I'd write a prototype (or a replacement if not too much work). With an example to examine it will be easier to see the pros and cons of a relational database.
As an aside, flat-file databases have their places since they are so much easier to "administer" than a true relational database. Keep an open mind. ;-)
I think you may have to lead by example - when people see that the "new" way is less work they will adopt it (as long as you don't rub their noses in it).
I would also ask yourself whether the old design is actually causing a problem or whether it is just aesthetically annoying. It's important to pick your battles - if the old design isn't causing a performance problem or making the system hard to maintain you may want to leave the old design alone.
Finally, if you do leave the old design in place, try and abstract the interface between your new code and the old database so if you do persuade your co-workers to improve the design later you can drop the new schema in without having to change anything else.
It is difficult to extract a whole lot except general frustration from the original question.
Yes, there are a lot of techniques and habits long-timers pick up over time that can be useless and even costly in light of technology changes. Some things that made sense when processing power, memory, and even disk was expensive can be foolish attempts at optimization now. It is also very much the case that people accumulate bad habits and bad programming patterns over time.
You have to be careful though.
Sometimes there are good reasons for the things those old timers do. Sadly, they may not even be able to verbalize the "why" - if they even know why anymore.
I see a lot of this sort of frustration when newbies come into an enterprise software development shop. It can be bad even when the environment is all fairly modern technology and tools. If most of your experience is in writing small-community desktop and Web applications a lot of what you "know" may be wrong.
Often there are requirements for transaction journaling at a level above what your DBMS may do. Quite often it can be necessary to go beyond DB transaction semantics in order to ensure time-sequence correctness, once and only once updating, resiliancy, and non-repudiation.
And this doesn't even begin to address the issues involved in enterprise or inter-enterprise scalability. When you begin to approach half a million complex transactions a day you will find that RDBMS technology fails you. Because relational databases are not designed to handle high transaction volumes you must often break with standard paradigms for normalization and updating. Conventional RDBMS locking techniques can destroy scalability no matter how much hardware you throw at the problem.
It is easy to dismiss all of it as stodginess or general wrong-headedness - even incompetence. But be careful because this isn't always the case.
And by the way: There are other models besides the RDBMS, and the alternative to an RDBMS is not necessarily "flat files" - contrary to the experience of of most coders today. There are transactional hierarchical DBMSs that can handle much higher throughput than an RDBMS. IMS is still very much alive in large IBM shops, for example. Other vendors offer similar software for different platforms.
Of course in a 4-man shop maybe none of this applies.
Sign them up for some decent trainings and then it's up to you to convince them that with new technologies a lot more is possible (or at least easier!).
But I think the most important thing here is that professional, certified trainers teach them the basics first. They will be more impressed by that instead of just one of their colleagues telling them: "hey, why not use this?"
Related post here.
The following may not apply in yr situation, but you make very little mention of technical details, so I thought I'd mention it...
Sometimes, if the access patterns are very different for current data than for historical data (I'm making this example up, but say that Current data is accessed 1000s of times per second, and accesses a small subset of columns, and all current data fits in less than 1 GB, whereas, say, historical data uses 1000s of GBs, is accessed only 100s of times per day, and access is to all columns),
then, what your co-workers are doing would make perfect sense, for performance optimization. By separating the current data (albiet redundantly) you can optimize the indices and data structures in that table, for the higher frequency access paterns that you could not do in the historical table.
Not everything that is "academically", or "technically" correct from a purely relational perspective makes sense when applied in an actual practical situation.

Developing a online exam application, how do I prevent cheaters?

I have the task of developing an online examination software for a small university, I need to implement measures to prevent cheating...
What are your ideas on how to do this?
I would like to possibly disable all IE / firefox tabs, or some how log internet activity so I know if they are googling anwsers...is there any realistic way to do such things from a flex / web application?
Simply put, no there is no realistic way to accomplish this if it is an online exam (assuming they are using their own computers to take the exam).
Is opening the browser window full screen an option? You could possibly also check for the window losing focus and start a timer that stops the test after some small period of time.
#Chuck - a good idea.
If the test was created in Flash/Flex, you could force the user to make the application fullscreen in order to start the test (fullscreen mode has to be user-initiated). Then, you can listen for the Flash events dispatched when flash exits fullscreen mode and take whatever appropriate action you want (end the test, penalize the user, etc.).
Flash/Flex fullscreen event info.
blog.flexexamples.com has an example fo creating a fullscreen-capable app.
Random questions and large banks of questions help. Randomizing even the same question (say changing the numbers, and calculating the result) helps too. None of these will prevent cheating though.
In the first case, if the pool is large enough, so that no two students get the same question, all that means is that students will compile a list of questions over the course of several semesters. (It is also a ton of work for the professors to come up with so many questions, I've had to do it as a TA it is not fun.)
In the second case, all you need is one smart student to solve the general case, and all the rest just take that answer and plug in the values.
Online review systems work well with either of these strategies (no benefit in cheating.) Online tests? They won't work.
Finally, as for preventing googling... good luck. Even if your application could completely lock down the machine. The user could always run a VM or a second machine and do whatever they want.
My school has always had a download link for the Lockdown browser, but I've never taken a course that required it. You can probably force the student to use it with a user agent check, but it could probably be spoofed with some effort.
Proctored tests are the only way to prevent someone from cheating. All the other methods might make it hard enough to not be worth the effort for most, but don't discount the fact that certain types of people will work twice as hard to cheat than it would have taken them to study honestly.
Since you can't block them from using google, you've got to make sure they don't have time to google. Put the questions in images so they can't copy and paste (randomize the image names each time they are displayed).
Make the question longer (100 words or more) and you will find that people would rather answer the question than retype the whole thing in google.
Give them a very short time. like 30-45 seconds. Time to read the question, think for a moment, and click either A, B, C, D, E,
(having just graduated from CSUN I can tell you scantron tests work.)
For essay questions? do a reverse google lookup (meaning put their answer into google as soon as they click submit) and see if you get exact matches. If so, you know what to do.
Will they always take the test on test machines, or will they be able to take the test from any machine on the network? If it will be specific machines, just use the hosts file to prevent them from getting out to the web.
If it is any machine, then I would look at having the testing backend change the firewall rules for the machine the test is running on so the machine cannot get out to the interwebs.
I'd probably implement a simple winforms (or WPF) app that hosts a browser control in it -- which is locked in to your site. Then you can remove links to browsers and lock down the workstations so that all they can open is your app.
This assumes you have control over the workstations on which the students are taking the tests, of course.
As a teacher, I can tell you the single best way would be to have human review of the answers. A person can sense copy/paste or an answer that doesn't make sense given the context of the course, expected knowledge level of the students, content of the textbook, etc, etc, etc.
A computer can do things like check for statistical similarity of answers, but you really need a person for final review (or, alternatively, build a massive statistical-processing, AI stack that will cost 10x the cost of human review and won't be as good ;-))
No, browsers are designed to limit the amount of damage a website or application can do to the system. You might be able to accomplish your goals through Java, an activex control, or a custom plugin, but other than that you aren't going to be able to 'watch' what they're doing on their system, much less control it. (Think if you could! I could put a spy on this webpage, and if you have it open I get to see what other websites you have open?)
Even if you could do this, using a browser inside a VM would give them the ability to use one computer to browse during the test, and if you could fix that they could simply use a library computer with their laptop next to it, or read things from a book.
The reality is that such unmonitored tests either have to be considered "open book" or "honor" tests. You must design the test questions in such a manner that references won't help solve the problems, which also means that each student needs to get a slightly different test so there is no way for them to collude and generate a key.
You have to develop an application that runs on their computer, but even then you can't solve the VM problem easily, and cannot solve the side by side computers or book problem at all.
-Adam
Randomize questions, ask a random set of questions from a large bank... time the answers...
Unless you mean hacking your site, which is a different question.
Short of having the application run completely on the user's machine, I do not believe there is a way to make sure they are not google-ing the answers. Even then it would be difficult to check for all possible loop-holes.
I have taken classes that used web based quiz software and used to work for a small college as well. For basic cheating prevention I would say randomize the questions.
Try adding SMS messages into the mix.
I agree with Adam, that even with the limitations that I suggested, it would still be trivial to cheat. Those were just "best effort" suggestions.
Your only hopes are a strong school honor code and human proctoring of the room where the test is being given.
As many other posters have said, you can't control the student's computer, and you certainly can't keep them from using a second computer or an iPhone along side the one being used for the test -- note that an iPhone (or other cellular device) can bypass any DNS or firewall on the network, since it uses the cellular provider's network, not the college's.
Good luck; you're going to need it.
Ban them from using any wireless device or laptop and keylog the machines?
You could enforce a small time window during which the test is available. This could reduce the chance that a student who knows the answers will be free to help one who doesn't (since they both need to be taking the test at the same time).
If it's math-related, use different numbers for different students. In general, try to have different questions for different copies of the test.
If you get to design the entire course: try to have some online homeworks as well, so that you can build a profile for each student, such as a statistical analysis of how often they use certain common words and punctuations. Some students use semi-colons often; others never, for example. When they take the test you get a good idea of whether or not it's really them typing.
You could also ask a couple questions you know they don't know. For example, list 10 questions and say they must answer any 6 out of the 10. But make 3 of the questions based on materials not taught in class. If they choose 2 or 3 of these, you have good reason to be suspicious.
Finally, use an algorithm to compare for similar answers. Do a simple hash to get rid of small changes. For example, hash an answer to a list of lower-cased 3-grams (3 words in a row), alphabetize it, and then look for many collisions between different users. This may sound like an obvious technique, but as a teacher I can assure you this will catch a surprising number of cheaters.
Sadly, the real trouble is to actually enforce punishment against cheaters. At the colleges where I have taught, if a student objects to your punishment (such as flunking them on the test in question), the administration will usually give the student something back, such as a positive grade change. I guess this is because the student('s parents) have paid the university a lot of money, but it is still very frustrating as a teacher.
The full screen suggestions are quite limited in their effectiveness as the user can always use a second computer or w/ multi monitor a second screen to perform their lookups. In the end it is probably better to just assume the students are going to cheat and then not count online tests for anything important.
If the tests are helpful for the students they will then do better on the final / mid term exams that are proctored in a controlled setting. Otherwise, why have them in the first place...
Make the questions and answers jpeg images so that you cannot copy and paste blocks of text into a search engine or IDE (if it is a coding test). This combined with a tight time limit to answer each question, say three minutes, makes it much harder to cheat.
I second what Guy said. We also created a Flex based examination system which was hosted in a custom browser built in .NET. The custom browser launched fullscreen, all toolbars were hidden and shortcuts were disabled.
Here is tutorial on how to create a custom browser with C# and VB.NET.
This will solve your problem. http://www.neuber.com/usermonitor/index.html
This will allow you to view the student's browser history during and after the test as well as look in on their screen during the test. Any urls visited during test time will be logged, so you can show them the log when you put a big F on their report card. :)
No one can stop people from cheating, but everyone can receive different questions altogether.
I prefer you buy available online scripts in market as starting point for it. This will save you time, cost and testing efforts.
Below is one of the fine scripts that I worked with and it worked like charm. Using this as base I developed a online testing portal of over 1000 users using computer adaptive test.
http://codecanyon.net/item/online-skills-assessment/9379895
It is a good starting point for people looking to develop Online Exam System.
I customized the script with the help of their support.

Requirements Gathering

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How do you go about the requirements gathering phase? Does anyone have a good set of guidelines or tips to follow? What are some good questions to ask the stakeholders?
I am currently working on a new project and there are a lot of unknowns. I am in the process of coming up with a list of questions to ask the stakeholders. However I cant help but to feel that I am missing something or forgetting to ask a critical question.
You're almost certainly missing something. A lot of things, probably. Don't worry, it's ok. Even if you remembered everything and covered all the bases stakeholders aren't going to be able to give you very good, clear requirements without any point of reference. The best way to do this sort of thing is to get what you can from them now, then take that and give them something to react to. It can be a paper prototype, a mockup, version 0.1 of the software, whatever. Then they can start telling you what they really want.
See obligatory comic below...
In general, I try and get a feel for the business model my customer/client is trying to emulate with the application they want built. Are we building a glorified forms processor? Are we retrieving data from multiple sources in a single application to save time? Are we performing some kind of integration?
Once the general businesss model is established, I then move to the "must" and "must nots" for the application to dictate what data I can retrieve, who can perform what functions, etc.
Usually if you can get the customer to explain their model or workflow, you can move from there and find additional key questions.
The one question I always make sure to ask in some form or another is "What is the trickiest/most annoying thing you have to do when doing X. Typically the answer to that reveals the craziest business/data rule you'll have to implement.
Hope this helps!
Steve Yegge talks fun but there is money to be made in working out what other people's requirements are so i'd take his article with a pinch of salt.
Requirements gathering is incredibly tough because of the manner in which communication works. Its a four step process that is lossy in each step.
I have an idea in my head
I transform this into words and pictures
You interpret the pictures and words
You paint an image in your own mind of what my original idea was like
And humans fail miserably at this with worrying frequency through their adorable imperfections.
Agile does right in promoting iterative development. Getting early versions out to the client is important in identifying what features are most important (what ships in 0.1 - 0.5 ish), helps to keep you both on the right track in terms of how the application will work and quickly identifies the hidden features that you will miss.
The two main problem scenarios are the two ends of the scales:
Not having a freaking clue about what you are doing - get some domain experts
Having too many requirements - feature pit. - Question, cull (prioritise ;) ) features and use iterative development
Yegge does well in pointing out that domain experts are essential to produce good requirements because they know the business and have worked in it. They can help identify the core desire of the client and will help explain how their staff will use the system and what is important to the staff.
Alternatives and additions include trying to do the job yourself to get into the mindset or having a client staff member occasionally on-site, although the latter is unlikely to happen.
The feature pit is the other side, mostly full of failed government IT projects. Too much, too soon, not enough thought or application of realism (but what do you expect they have only about four years to make themselves feel important?). The aim here is to work out what the customer really wants.
As long as you work on getting the core components correct, efficient and bug-free clients usually remain tolerant of missing features that arrive in later shipments, as long as they eventually arrive. This is where iterative development really helps.
Remember to separate the client's ideas of what the program will be like and what they want the program to achieve.
Some clients can create confusion by communicating their requirements in the form of application features which may be poorly thought out or made redundant by much simpler functionality then they think they require. While I'm not advocating calling the client an idiot or not listening to them I feel that it is worth forever asking why they want a particular feature to get to its underlying purpose.
Remember that in either scenario it is of imperative importantance to root out the quickest path to fulfilling the customers core need and put you in a scenario where you are both profiting from the relationship.
Wow, where to start?
First, there is a set of knowledge someone should have to do analysis on some projects, but it really depends on what you are building for who. In other words, it makes a big difference if you are modifying an enterprise application for a Fortune 100 corporation, building an iPhone app, or adding functionality to a personal webpage.
Second, there are different kinds of requirements.
Objectives: What does the user want to accomplish?
Functional: What does the user need to do in order to reach their objective? (think steps to reach the objective/s)
Non-functional: What are the constraints your program needs to perform within? (think 10 vs 10k simultaneous users, growth, back-up, etc.)
Business rules: What dynamic constraints do you have to meet? (think calculations, definitions, legal concerns, etc.)
Third, the way to gather requirements most effectively, and then get feedback on them (which you will do, right?) is to use models. User cases and user stories are a model of what the user needs to do. Process models are another version of what needs to happen. System diagrams are just another model of how different parts of the program(s) interact. Good data modeling will define business concepts and show you the inputs, outputs, and changes that happen within your program. Models (and there are more than I listed) are really the key to the concern you list. A few good models will capture the needs and from models you can determine your requirements.
Fourth, get feedback. I know I mentioned this already, but you will not get everything right the first time, so get responses to what your customer wants.
As much as I appreciate requirements, and the models that drive them, users typically do not understand the ramifications of of all their requests. Constant communication with chances for review and feedback will give users a better understanding of what you are delivering. Further, they will refine their understanding based on what they see. Unless you're working for the government, iterations and / or prototypes are helpful.
First of all gather the requirements before you start coding. You can begin the design while you are gathering them depending on your project life cicle but you shouldn't ever start coding without them.
Requirements are a set of well written documents that protect both the client and yourself. Never forget that. If no requirement is present then it was not paid for (and thus it requires a formal change request), if it's present then it must be implemented and must work correctly.
Requirements must be testable. If a requirement cannot be tested then it isn't a requirement. That means something like, "The system "
Requirements must be concrete. That means stating "The system user interface shall be easy to use" is not a correct requirment.
In order to actually "gather" the requirements you need to first make sure you understand the businness model. The client will tell you what they want with its own words, it is your job to understand it and interpret it in the right context.
Make meetings with the client while you're developing the requirements. Describe them to the client with your own words and make sure you and the client have the same concept in the requirements.
Requirements require concise, testable example, but keep track of every other thing that comes up in the meetings, diagrams, doubts and try to mantain a record of every meeting.
If you can use an incremental life cycle, that will give you the ability to improve some bad gathered requirements.
You can never ask too many or "stupid" questions. The more questions you ask, the more answers you receive.
According to Steve Yegge that's the wrong question to ask. If you're gathering requirement it's already too late, your project is doomed.
High-level discussions about purpose, scope, limitations of operating environment, size, etc
Audition a single paragraph description of the system, hammer it out
Mock up UI
Formalize known requirements
Now iterate between 3 and 4 with more and more functional prototypes and more specs with more details. Write tests as you go. Do this until you have functional software and a complete, objective, testable requirements spec.
That's the dream. The reality is usually after a couple iterations everybody goes head-down and codes until there's a month left to test.
Gathering Business Requirements Are Bullshit - Steve Yegge
read the agile manifesto - working software is the only measurement for the success of a software project
get familiar with agile software practices - study Scrum , lean programming , xp etc - this will save you tremendous amount of time not only for the requirements gathering but also for the entire software development lifecycle
keep regular discussions with Customers and especially the future users and key-users
make sure you talk to the Persons understanding the problem domain - e.g. specialists in the field
Take small notes during the talks
After each CONVERSATION write an official requirement list and present it for approving. Later on it would be difficult to argue against all agreed documentation
make sure your Customers know approximately what are the approximate expenses in time and money for implementing "nice to have" requirements
make sure you label the requirements as "must have" , "should have" and "nice to have" from the very beginning, ensure Customers understand the differences between those types also
integrate all documents into the latest and final requirements analysis (or the current one for the iteration or whatever agile programming cycle you are using ... )
remember that requirements do change over the software life cycle , so gathering is one thing but managing and implementing another
KISS - keep it as simple as possible
study also the environment where the future system will reside - there are more and more technological restraints from legacy or surrounding systems , since the companies do not prefer to throw to the garbage the money they have invested for decades even if in our modern minds 20 years old code is garbage ...
Like most stages of the software development process its iteration works best.
First find out who your users are -- the XYZ dept,
Then find out where they fit into the organisation -- part of Z division,
Then find out what they do in general terms -- manage cash
Then in specific terms -- collect cash from tills, and check for till fraud.
Then you can start talking to them.
Ask what problem they want you want to solve -- you will get an answer like write a bamboozling system using OCR with shark technoligies.
Ignore that answer and ask some more questions to find out what the real problem is -- they cant read the till slips to reconcile the cash.
Agree a real solution with the users -- get a better ink ribbon supplier - or connect the electronic tills to the network and upload the logs to a central server.
Then agree in detail how they will measure the success of the project.
Then and only then propose and agree a detailed set of requirements.
I would suggest you to read Roger-Pressman's Software Engineering: A Practitioner's Approach
Before you go talking to the stakeholders/users/anyone be sure you will be able to put down the gathered information in a usefull and days-lasting way.
Use a sound-recorder if it is OK with the other person and the information is bulky.
If you heard something important and you need some reasonable time to write it down, you have two choices: ask the other person to wait a second, or say goodbye to that precious information. You wont remember it right, ask any neuro-scientist.
If you detect that a point need deeper review or that you need some document you just heard of, make sure you make a commitment with the other person to send that document or schedule another meeting with a more specific purpose. Never say "I'll remember to ask for that xls file" because in most cases you wont.
Not to long after the meeting, summarize all your notes, recordings and fresh thoughts. Just summarize it rigth. Create effective reminders for the commitments.
Again, just after the meeting, is the perfect time to understand why the gathering you just did was not as right as you thought at the end of the meeting. That's when you will be able to put down a lot of meaningful questions for another meeting.
I know the question was in the perspective of the pre-meeting, but please be aware that you can work on this matters before the meeting and end up with a much usefull, complete and quality gathering.
I've been using mind mapping (like a work breakdown structure) to help gather requirements and define the unknowns (the #1 project killer). Start at a high level and work your way down. You need to work with the sponsors, users and development team to ensure you get all the angles and don't miss anything. You can't be expected to know the entire scope of what they want without their involvement...you - as a project manager/BA - need to get them involved (most important part of the job).
There are some great ideas here already. Here are some requirements gathering principles that I always like to keep in mind:
Know the difference between the user and the customer.
The business owners that approve the shiny project are usually the customers. However, a devastating mistake is the tendency to confuse them as the user. The customer is usually the person that recognizes the need for your product, but the user is the person that will actually be using the solution (and will most likely complain later about a requirement your product did not meet).
Go to more than one person
Because we’re all human, and we tend to not remember every excruciating detail. You increase your likelihood of finding missed requirements as you talk to more people and cross-check.
Avoid specials
When a user asks for something very specific, be wary. Always question the biases and see if this will really make your product better.
Prototype
Don’t wait till launch to show what you have to the user. Do frequent prototypes (you can even call them beta versions) and get constant feedback throughout the development process. You’ll probably find more requirements as you do this.
I recently started using the concepts, standards and templates defined by the International Institute of Business Analysts organization (IIBA).
They have a pretty good BOK (Book of Knowledge) that can be downloaded from their website. They do also have a certificate.
Requirements Engineering is a bit of an art, there are lots of different ways to go about it, you really have to tailor it to your project and the stakeholders involved. A good place to start is with Requirements Engineering by Karl Wiegers:
http://www.amazon.com/Software-Requirements-Second-Pro-Best-Practices/dp/0735618798/ref=pd_bbs_sr_2?ie=UTF8&s=books&qid=1234910330&sr=8-2
and a requirements engineering process which may consist of a number of steps e.g.:
Elicitation - for the basis for discussion with the business
Analysis and Description - a technical description for the purpose of the developers
Elaboration, Clarification, Verification and Negotiation - further refinement of the requirements
Also, there are a number of ways of documenting the requirements (Use Cases, Prototypes, Specifications, Modelling Languages). Each have their advantages and disadvantages. For example prototypes are very good for elicitation of ideas from the business and discussion of ideas.
I generally find that writing a set of use cases and including wireframe prototypes works well to identify an initial set of requirements. From that point it's a continual process of working with technical people and business people to further clarify and elaborate on the requirements. Keeping track of what was initially agreed and tracking additional requirements are essential to avoid scope creep. Negotiation plays a bit part here also between the various parties as per the Broken Iron Triangle (http://www.ambysoft.com/essays/brokenTriangle.html).
IMO the most important first step is to set up a dictornary of domain-specific words. When your client says "order", what does he mean? Something he receives from his customers or something he sends to his suppliers? Or maybe both?
Find the keywords in the stakeholders' business, and let them explain those words until you comprehend their meaning in the process. Without that, you will have a hard time trying to understand the requirements.
i wrote a blog article about the approach i use:
http://pm4web.blogspot.com/2008/10/needs-analysis-for-business-websites.html
basically: questions to ask your client before building their website.
i should add this questionnaire sheet is only geared towards basic website builds - like a business web presence. totally different story if you are talking about web-based software. although some of it is still relavant (e.g. questions relating to look and feel).
LM
I prefer to keep my requirements gathering process as simple, direct and thorough as possible. You can download a sample document that I use as a template for my projects at this blog posting: http://allthingscs.blogspot.com/2011/03/documenting-software-architectural.html

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