Participants and Sample Size
“5 users will uncover approximately 80% of all usability problems”
– Nielsen Norman Group
Sample Size & Reliability
The more people find the same problem, the more reliable the data set becomes.
Multiple Rounds of Testing
Multiple round of testing on 5 different users covers more issues than a single round of testing with the same number of users.
|User 1||User 6||User 11||User 1||User 9|
|User 2||User 7||User 12||User 2||User 10|
|User 3||User 8||User 13||>||User 3||User 11|
|User 4||User 9||User 14||User 4||User 12|
|User 5||User 10||User 15||User 5||User 13|
|User 6||User 14|
|User 7||User 15|
|User 8||User 16|
|of issues||of remaining issues||of remaining issues||
Selecting the right people
You need to select the participants based on the following criteria:
- User Profiles
- General Data about your User base
- The users understanding of the product.
- The Familiarity with the Product or Type of Product.
- Amount of overall Experience
And Recruiting criteria:
- Sample Size – how many people can you effort to bring in to test.
- Characteristics of the user – about the criteria being defined.
- Number of Participants for Each Personas or Characteristics.
|Quick simple functions||Provide the partecipant context and direction|
|Easily completed without any background information given||Set the stage, tell the story|
|Find the Search button||Increase overall understanding|
|Where would one go to out information about specific terms||Help the user apply the situation to themselves|
|Give them an action to perform|
- Uses the vocabulary that the participant uses.
- The actions are clear and precise.
- Provides all the details needed to complete the goal.
- Does not provide steps and definitely does not give away the answer.
- You would like to buy a car, you would like to lease it for 36 months term with 1500 down. How would you do this?
Rating your results
a. Easy or under a minute to find/answer – – – —2 points
b. Difficult, takes 1-2 minutes to find/answer —-1 point
c. Fail, takes over 2 minutes to find/answer ——0 point