Evaluation: Cognitive Walkthrough

Another way to evaluate the word scanner prototype is to do a cognitive walkthrough. In this process a series of steps are followed which a potential user would have to do to carry out an action on the word scanner. These steps can then be evaluated to see where possible problems may lie.

A cognitive walkthrough can be used to indicate issues that may arise when a user tries to learn how to use the device without the need of documentation.

Here is my adapted version of the cognitive walkthrough for the main use cases of the word-scanning device with the main users being children from 7-11 year olds. The guide I am using can be found here

The task:
To scan a word.

Actions required:

1. Find a word to scan with the device.
2. Place the head of the device on the first space on the left.
3. Press and hold the scan button.
4. Move the pen slowly to the right across the word.
5. When the head of the pen has reached the first space after the word, release the scan button.

Evaluation:

If the user wanted to scan a word with the device, then the sequence of actions will be required based on our prototype. The scan button has the word ‘scan’ written across it so the targeted user can easily identify this button. Pressing this button has the direct action of starting the scanning device. A user may not initially think that the button has to be held down during the scanning process and may assume you just press it once to start a scan.

The main control for this case is the ‘scan’ button, which is clearly visible and brightly coloured on the device. It is the only big button on the device and is clearly labelled. As the device is a word scanner the word ‘scan’ on the main control button should indicate to a user that this is the control to activate the scanner.

Once scan has been performed there is an indication on the LCD screen whether the scan was successful by showing the user the word scanned, or was unsuccessful producing an error message. It is unclear to the user when the scanning of a word is starting or has finished. The only feedback given back to the user is en error message or a scanned word on the LCD screen when finished.


The task:
To access the dictionary definition after a successful scan.

Actions required:

1. Hold the device horizontally.
2. Use the scroll button beside the screen and move the scroll button down. This in turn will move the highlighted menu entry down.
3. Scroll down to ‘Dictionary’ on the menu.
4. Select the ‘Dictionary’ by pressing the scroll button in.

Evaluation:

The actions for this case will only be required if the user wants to access the definition of the word they have just scanned into the device. The dictionary option in the main menu is only available after a successfully scanned in word.

The user should be able to see the menu item clearly in the menu. The main reason for this is because only 2 items of the menu are shown at any one time as the user scrolls through them due to the design of the LCD screens interface. There are also only a few items on the menu system. The scroll button on the device is very similar to the scroll button on a standard computer mouse. At first the user may not understand the scroll buttons controls to get through the menus or run though definitions, but after playing with the device it should become clear to the user especially if they use the scroll button on a mouse.

If the user is trying to get the definition of the word they have scanned, there could be slight confusion as to what the resulting action will be, revealing the definition of the word. As the menu system only says ‘Dictionary’ rather than clarifying that there will be only the definition of the scanned in word.

When the user selects the dictionary after a scan, it should be clear that the feedback given on the screen is the definition of the word. It is also useful to note that the scanned word is always at the top of the screen so the user always knows what the definition relates to.

The task:
To access the thesaurus entries for the word after a successful scan.

Actions required:

1. Hold the device horizontally.
2. Use the scroll button beside the screen and move the scroll button down. This in turn will move the highlighted menu entry down.
3. Scroll down to ‘Thesaurus’ on the menu.
4. Select the ‘Thesaurus’ by pressing the scroll button in.

Evaluation:

This task has similar actions to obtaining the dictionary definition of a scanned in word. The actions for this case will only be required if the user wants to access the thesaurus entries of the word they have just scanned into the device. The thesaurus option in the main menu is only available after a successfully scanned in word.

The user should be able to see the menu item clearly in the menu for the same reasons as the dictionary definition explained above.

If the user is trying to get the thesaurus entries of a word they have scanned, there could be slight confusion as to what the resulting action will be, displaying a list of alternative words. As the menu system only says ‘Thesaurus’ rather than clarifying that there will only be alternative words displayed for the scanned in word.

When the user selects the thesaurus after a scan, it should be clear that the feedback given on the screen is alternative words that can be used instead of the word that was scanned into the device.