Skip to main content

Testing for correctness

Testing for correctness

Testing for correctness usually means:

  • Ensuring that your user can download a completed form, or otherwise reach an end screen
  • Ensuring that invalid input (however you define it) is not submitted
  • Ensuring that the user does not see an error screen
  • Ensuring that your form is "legally" correct--that is, that the business rules of your form are correctly implemented

Testing for correctness is important throughout the form development process. Errors can creep in at any stage. Errors may also be "regressions". A regression is a bug that comes back after being fixed. A feature might be complete and work one day, and a change that you make to seemingly unrelated code can reintroduce an error. That means you will want a plan to run and re-run your tests multiple times. Automated tests can help make the re-running step realistic.

Keep in mind that reaching the state of "zero" bugs is almost impossible. Instead, think about testing the most common situations and provide a way for your user to let you know about bugs you didn't discover in advance so that you can quickly resolve them.

Software tests usually come in two varieties:

  1. Unit tests, in which a specific function or method is tested in isolation
  2. End to end tests, in which multiple full "paths" through your tool are tested to ensure that the different components work in combination.

Unit tests can be very helpful for testing Python code, but less useful in the most common kinds of guided interviews which involve little code. Instead, you will mostly rely on end-to-end tests of the entire form. End-to-end testing can be tedious, but it's important to release software into the world that is relatively free of bugs. Bugs will reduce user confidence in your tool.

The ALKiln framework, developed by the Document Assembly Line Project, provides a method for automating end-to-end tests in a relatively flexible way. However, setting up an ALKiln test is still an advanced task. Most users will get by with a series of manual end-to-end tests that concentrate on getting good "coverage" of the most common paths through your guided interview.

The next section discusses a simple manual method of conducting end-to-end tests by developing realistic user scenarios.

When is testing complete?

No software has finished testing before it is in the hand of real-world users. Your users will find bugs that the most carefully planned testing will miss. You need a plan to gather feedback from your app once it is released in order to catch these late bugs.

What is scenario-based testing?

The goal of testing is to validate that software works, and works correctly. In scenario-based testing, we try to validate software by running through the features or workflow of the software as if we were a real-world user of the tool.

Benefits and tradeoffs

The benefit of scenario-based testing is that if done correctly, you will quickly identify the most important issues in your software with a relatively small amount of work. The negative is that you will miss some bugs. On the other hand, identifying all bugs in software is both logically impossible and an inappropriate tradeoff of resources for most projects.

Creating user scenarios

There are 5 basic steps to scenario-based testing:

  1. Brainstorm the profiles of real users of your tool. Think about who they are and what goals they may have.
  2. Ensure you generate profiles that will encounter multiple branches of your tool. For example: if your tool is for helping someone file for divorce, at least one profile might be for a user with children, and one without.
  3. Now, think broadly about any fact patterns that your user profiles may have. Fact patterns are less about who the user is, and more about a temporary situation they are in. For example: a user profile might be for a tenant who lives in public housing. A fact pattern might be that they owe rent or are being evicted for violating their lease.
  4. Reason about the combination of your profiles and fact patterns, and eliminate any that overlap. These become the scenarios that you will test. You want to test most logical branches of your interview with the combination of users and fact patterns.
  5. Write a brief narrative prompt for your tester that describes each scenario.

For a typical short form, you should end up with 5-10 scenarios. A very long or complex form may end up with many more. Try to think about how and whether you can isolate different sections of the tool to avoid an impossibly large combinatorial explosion of scenarios. If your tool produces some combination of 5 forms, for example, make sure to test your scenarios on each form, but not necessarily each combination of possible forms, which would immediately increase your scenarios by a factor of 25.

What features should be tested, and in which combinations?

The goal of scenario-based testing is to approximate real-world use cases.

Yet it's also important to provide good coverage of the features that your tool has and makes available, because a user may decide to make use of functionality that you did not anticipate.

Make sure your testing scenarios cover:

  1. Inputs that trigger a new branch of your form (showing or hiding a screen or follow-up question).
  2. Inputs that trigger a new form.
  3. Inputs that trigger computed values (as opposed to ones that are copied into the form literally, without being transformed in any way).
  4. Inputs that trigger an addendum. These can generally all be tested at once.
  5. Reason in advance about combinations of inputs that may interact. For example: code that triggers an addendum is probably independent of code that shows or hides follow-up questions. You may be able to safely test all of the addenda at once.

One way to do this might be to make a matrix. Only some of the overlapping features will need to be tested in combination. Write down each field in the columns and rows of a table, and mark an x if you think that combination of row and column needs a test.


 Has 1 childHas assetsLives out of state
Has 1 childxxx
Has assets(dupe)x(not relevant)
Lives out of state(dupe)(not relevant)x

This matrix produced 5 combinations that our user scenarios should test. If this list is too long, we may be able to remove even more tests that are truly independent and don't need to be tested in combination. We can also combine some features into a single testing scenario.

Developing a testing strategy

You should now have between 5-10 scenarios to test. You should come up with at least two independent testers who will each run each scenario, with a total of 10-20 runs of your tests.

Running the tests

Your tester should now have a set of user scenarios as prompts for their testing. The prompts will be narratives. For example, if the form is for an eviction, the user scenario might be:

Terry Tenant lives in public housing. She is being evicted for non-payment of rent. Her landlord didn't send her a notice to quit. Her goal is to file an Answer in her eviction case.

The tester should look at the scenario as they navigate your tool, and answer all questions as best as they can to reflect the facts that the scenario provides. They will enter random (but realistic) input as well as they can.

Because there will be multiple tests by different testers, the random input will help catch more errors than a list of specific inputs for each field.

Recording the results of your tests

As your tester navigates the tool, they should write down the answers that they give on each screen. If they run into an issue, they should write down the issue that they encounter.

It can help to provide your tester a spreadsheet to record their inputs. That will help you reproduce the bugs and confirm that they are fixed. A narrative is fine as well. Perhaps your tester just opens a Word document and writes down their choices.

In some instances, a video recording may be useful. If your tester opens a Zoom meeting session and shares their screen, they can record the testing session. If they run into any bugs, the recording can be used to trace their steps.

You should also provide your tester with a place to record feedback. A Google Form is a good place to do that. Each page of the interview should have a unique ID that is visible and will help record feedback and errors in the right place.

Sample tester instructions

Dear tester, thank you for agreeing to test my tool! Please read the list of
user-scenarios below. I would like you to run through the form following each
scenario. Please either record your screen on Zoom as you navigate the form, or
write down your inputs on each screen. Each screen has a unique ID shown in
red after the words "Page ID". Use this to identify the screen. If you run
into a bug, try to explain what you did to trigger it, and copy and paste any
error text you ran into.

You can use this form [INSERT LINK] to tell me about the bugs you found.
You can use this spreadsheet [INSERT LINK] to record the tests that you ran.

The scenario does not cover all of the facts. I would like you to imagine that
you are the user described in the scenario, and enter any choices that make
sense to you. Your exact choice is not important. What is most important is
that we get enough different choices from all of the testers to catch most of
the bugs.

For fields that allow a lot of text, you may want to use this
Lorem Ipsum generator to see how the text input is handled.

Review your tests and iterate

Once you have finished a round of testing, look over the results and the variety of inputs that were entered. You made an assumption about how well the tests would cover the features of your tool.

  1. How well did your tests cover the different logical branches of your tool?
  2. Did your tests encounter edge cases that you can safely eliminate, simplifying the tool and reducing the scope for future tests? Sometimes the safest feature is one that doesn't exist! If your functionality is very hard to test, you may consider a simpler substitute for the functionality.
  3. Did you notice any pattern of errors that would lead you to redesign either your tool or the testing scenarios?

Fix any bugs and confirm them by re-running the test with the facts that the tester used.

Use the information you learned to decide if more tests need to be run, perhaps with new scenarios.

Further reading

The links below describe some more details about what scenario-based testing is and how to use it.

  1. Wikipedia
  2. Geeks for Geeks
  3. Guru99