Assignment 3: Heuristic UI evaluation and redesign

Due: Sunday, 29 September 2019, 11:55 PM

Edit log:

  • Added 26 Sept: Instruction on how many usability problems to provide in Task 3.

This assignment will give you practical experience on the use of design/usability heuristics for UI evaluation and UI design, and you will get to suggest improvements to Design heuristics are useful, because they can be used both during design, as guidelines, and in evaluation, to assess the UI’s usability without needing to arrange user studies. 


You will be analysing the UI of, which is a website that provides different time-related little tools and services.

Screenshot of of time and date website

Screenshot of's landing page.

TASK 1: Problem scoping for’s time zone converter using PACT

In this task we suppose that the users go to the to use the time zone converter. 

Use the PACT framework to make educated guesses on what the typical users are like (P), what sub-aspects in their activity (A) are important for using’s time zone converter function, in what context (C) the task is probably carried out, and what technology (T) the users will be using. You do this by choosing one important aspect from each sub-aspect of PACT:

  • People (P): physical differences, psychological differences and usage differences
  • Activities (A): temporal aspects, cooperation, complexity, security critical and the nature of the content
  • Context (C): social context, organizational context and physical circumstances
  • Technologies (T): input, output, communication and content

You don't need to overspecify your scope. I.e., don't define, for example, that with respect to people (P), you are only going to focus on left-handed teenagers; that would not make any sense.

Present the results of your analysis using the following table template:



Explanation why this is an important sub-aspect in this task





Here is an example answer from a different task domain, if the task would be bus trip planning using Helsinki area journey planner:



Explanation why this is an important sub-aspect in journey planning


Psychological differences

The system is intended for a large group of people with different computer skills. It therefore has to be simple to use and offer good guidance.


Temporal aspects

People may want to use the system in a hurry, just before planning to take a bus. The system has to provide answers fast and reliably.


Physical circumstances

Taking a bus trip involves leaving the comfort of our homes and venturing outside. This means that people may use the service outdoors.



As mentioned above, people may be using it on the go, which means that people may use the service from a mobile phone.

TASK 2. Heuristic evaluation 

Now that you have an understanding about the aspects that matter when using the time zone converter on, you will try to detect issues with the site with the help of heuristics.

Look at Nielsen’s heuristics (e.g., from lecture slides, or search them from the Internet), and decide which three heuristics are the most important ones to use in evaluation. Your choice of the heuristics must be based on your PACT analysis, and should be justified sufficiently. Please write full sentences, not bullet points.

Present your choice of three heuristics using the following table format:


Explanation why you chose this heuristic

Here is an example answer from a different task domain, if the task would be bus trip planning using Helsinki area journey planner (note that in this example, we gave an example of only one heuristic):


Explanation why you chose this heuristic

Error prevention

In the PACT analysis, I emphasized the Temporal Aspects under Activities. Users may be in a rush, checking the app as they are running to catch the bus. This means that they are maybe less attentive and the risk of errors is high (e.g. going to the wrong stop, taking the wrong bus). Therefore, error prevention heuristic is especially relevant for evaluating the usability of the journey planner.


TASK 3. Finding problems and proposing improvements with heuristics

After your selection, carry out the heuristic evaluation using these three heuristics. Analyse the usage of’s main page and time zone conversion tool and identify usability problems.

Present your findings using a screenshot from and the following table. In the screenshot, add numbers to designate places in the UI to which you are referring to. If you are referring to some larger issue that does not relate to any particular position in the interface, you don’t need to place the number on the screenshot.

Added 26 Sept: In task 3, where the goal is to identify usability problems based on the three heuristics that you have chosen, the quality is more important than quantity. In an actual heuristic usability evaluation, there can be dozens of identified problems, and it would be important also to prioritise them. But that is not required here. Therefore, for each of the tree heuristics, identifying 2 usability problems is sufficient. That is, 3x2 usability problems. 

[insert your screenshot annotated with numbers]

Link the annotations to the picture in the following form:


Related to which heuristic

Description of the problem (1-3 sentences)




Now that you have identified problems in the interface, select one problem from the table, and propose an improvement of it.

Tell us:

  1. Which problem you are addressing from the table above
  2. What your improvement would be like. You do not need to draw an improvement, but if it helps communicating your idea, you can do that.
  3. Explain how your solution solves the usability problem you identified.

How to return this assignment

Your submission must be returned as a PDF, and it should include 1) a filled out table for Task 1, and 2) a filled out table for Task 2, and 3) filled out table and an improvement proposal for Task 3.

This assignment is carried out independently.

Return your assignment by 23:55 on Sunday 29 September 2019 as a PDF via this page.

Assignment 3 grading:

Full point answer:
The student did all three tasks outlined in the exercise well,
(TASK 1) In the problem formulation the PACT framework was used well to describe the various important characteristics of people, activities, contexts and technologies that relate to the use of time zone converter function referencing the sub-aspects of PACT.

(TASK 2) The student chose three of the Nielsen’s heuristics and explained why they are relevant to the use of the time zone converter, linking to observations made in the PACT assessment. The student conducted the heuristic evaluation using the three heuristics.

(TASK 3) The student described the problems well, indicating on the screenshot where the problems are. They selected one problem, and described verbally or visually what the improvement would be. They explain sufficiently how the solution solves the problem they identified earlier.

Marks will be deducted for missing tasks, for not utilizing the PACT framework, for insufficient or unclear reasoning and justification and not using the heuristic.