Assignment 9: Multimodal analysis of an app for bicycle messengers

Due: Sunday, 17 November 2019, 11:55 PM

Edit log:

  • 12 Nov 22:19: Added an intro to multiple resources theory.

This assignment both lets to synthesize some of the things you have learned in this course already and also lets you apply them to a possible design challenge.

Bike messenger by Mal Booth. Attribution-NonCommercial-ShareAlike 2.0 Generic (CC BY-NC-SA 2.0)

Photo credit: Bike messenger by Mal Booth. Attribution-NonCommercial-ShareAlike 2.0 Generic (CC BY-NC-SA 2.0)

Scenario: Let’s assume that a company is developing a system for a company whose bicycle messengers pick parcels and deliver them to different parts in a city. The goal is to keep the messenger all the time occupied in either delivering parcels or cycling to a new location for picking-up of the next parcel. Because of this, the system for the messengers should be usable especially while the messenger is cycling: from a device mounted on the bike’s handlebar, or some other ways. The lecture L9 gives you starting points for thinking different multimodal design alternatives.

Organize your report along the following sections.

1. Task analysis

Considering the work of a bike messenger, choose one situation from cycling in traffic. This situation should be typical for and/or critically important for successful execution of a bike messenger’s manoeuvring in traffic. Don’t consider interaction with the system-to-be-built in this situation; consider only cycling in the middle of city traffic.

For that situation, conduct a hierarchical task analysis (see L2 and A2 to refresh your memory). The purpose is to map the structure of the activity in the situation. If your chosen setting is very complex and involves simultaneous tasks (e.g., navigating through a crossroads and also doing something else at the same time), create two separate diagrams because parallel activities are hard to model within a single HTA. 

Describe (with 1-3 sentences) the situation that you chose and why you chose that one in particular. Include the HTA diagram(s) in your report.

2. Multimodal constraints

Now start considering the opportunities for adding the new system into that situation. Answer the following questions in your report:

  • What type of attention (focused / divided) is required from the messenger in the most important sub-tasks of your HTA diagram(s)?
  • What motor (e.g., hand movement) constraints apply in the same sub-tasks?
  • Following the multiple resources theory, what resources (modalities, processing stages, responses) are already in use in the same sub-tasks?

Added 12 Nov: A short introduction to Multiple Resources Theory (MRT):

MRT is a very useful model for an analysis of cognitive conflicts in multitasking situations. The theory, presented by Wickens (2002) divides human cognition into four dimensions: modalities (visual vs. auditory), stages of processing (perception, cognition (i.e., information processing), responding), response type (spatial, verbal), and focal vs ambient content (this one within the visual modality only).

The dimensions can be visualised as follows:

Multiple resources theory displayed using a cube

MRT can be used, for example, when a designer or a researcher wants to understand what modalities a user can have available for interaction with a device while they are at the same time performing another action too (as in our exercise is the case). If the activity and the interaction require the same cognitive capacities along several dimensions, the interaction with the device is going to be very difficult or even impossible without destroying the (primary) activity. These conflicts are illustrated in the image above as conflicts of different kinds:

  • 3D conflict (orange dots): two activities requiring simultaneous visual verbal perception: for example reading two texts at the same time.
  • 2D conflict (purple dots): two activities requiring visual verbal processing, one being perception and the other responding: for example reading one text while writing lyrics of a well-remembered song.
  • 1D conflict (blue dots): two activities requiring visual processing, one being verbal perception and the other spatial responding: for example reading some text while also walking on a busy street.
  • No conflict (gray dots): one activity requiring auditory verbal responding (e.g., repeating what one hears another person saying) and the other requiring visual spatial perception (e.g., waiting for a green signal in traffic lights).

The fewer thre are dimensions in conflict between two tasks, the better is their simultaneous execution.

More about MRT:

  • Wickens, C. W. (2002). Multiple resources and performance prediction. Theoretical Issues in Ergonomics Science, 3(2), 159-177. PDF
  • 3. Identifying a perceptual/attentional/interaction “niche” for the system

    Again using the multiple resources theory diagram, identify modalities that would best be available for safe, efficient robust etc. interaction with the new system in the chosen situation. Populate the resource diagram with the constraints that you identified in Step 2.

    Then find out:

    • What resources are left for the messenger for entering input 
    • What resources are left for the messenger to perceive and interpret system’s output

    In this last step of the report, present the populated resource diagram and the most suitable input and output modalities for interaction with the system.