What's On Your Mind..?

The think aloud protocol is a method introduced by Clayton Lewis in the early 1980's. This method is used in usability evaluations to gain a better understanding of what goes on in the minds of the users while they are using the software.

The steps in this method are simple. First, we recruit representative users as participants. Then, we ask the participants to carry out a series of representative tasks with the software. While they are carrying out these tasks, participants are encouraged to say everything that comes to mind. These spoken thoughts may be "why is the button red?" or "where can I search for the item?" or "that table looks great" or "I'm stuck and I'm not sure what to do next". Generally, participants are asked to verbalize what they are looking at, what they are thinking, what they are doing, and what they are feeling.

This way, if the user does something unexpected, we can review what the user was thinking and doing at that time and try to rationalize and justify the unexpected behaviour.

The goal of this protocol is to make the participants' thought processes as transparent as possible so researchers can gain a better understanding of the participants' cognitive processes during software use.

A Closer Look: Disadvantages

While the protocol is low cost and easy to use, many participants do not naturally think aloud during software use, especially in the presence of others. Therefore, some training and a lot of encouragement will be needed in the beginning of adopting this method.

Also, we have to be weary of whether the participants are providing filtered statements versus their raw reactions. Most people need to be prompted to keep them thinking aloud continuously.

Lots Of Advantages

A key advantage of the think aloud protocol is that no extra equipment is needed so it is convenient and cheap.

The method works well for researchers who aren't necessarily trained in facilitation. So long as the researcher who asks questions or prompts the user for the thought processes aren't using biased phrases, the method is quite robust to a variation of moderator skills.

It is a flexible method that can be used in any stage of the software development lifecycle.

Although it is unnatural, the method is rather easy to learn. Most participants have to know they should just say whatever comes to mind, even if they feel they might say something that is not useful for the study. If training is put in at the beginning of the study, most of the time, participants will get the hang of it in just a few minutes.

Most importantly, if you work in a team of developers and/or designers who think they built the best software, allowing them to listen in on a think aloud session could provide them with clear evidence that their designs might not be as effective as they think. This kind of feedback provides developers/designers convincing data that can be used to help them learn how users actually think.

What To Do With The Data?

The purpose of using the think aloud protocol is to evaluate software usability. This approach in particular helps identify points of frustration or confusion in the software.

Therefore, video recording is often used to log what the user did, when, the actions that triggered certain events, what was spoken, etc. Note that the video recording can be a screen recording without the participant being visible in the video (which is often easier for the participant to consent to). Video data analysis can be extremely time consuming. So an alternative is to ensure that the facilitator takes good and detailed notes.

Thereafter, some kind of qualitative analysis will take place, with the ultimate goal of generating a list of usability issues that are ranked in some way so the development team can focus on improving the software.