The procedure

This section describes, step by step and in detail, the procedure that was followed to carry out the experiments. The first step was to select date(s), time(s) and location(s) to run the experiments.

5.5.1 Set the date(s), time(s) and location(s)

A date, time and location was selected that was convenient for the participants to take part in the experiments. The main location chosen was the research section of the Georgia State University (GSU) library (i.e. the location of the initial experiments). The only real requirement was access to a power outlet for our test laptop and a desk or table. Once the date(s), time(s) and location(s) were selected, we next had to acquire the participants. Each participant took part in the experiment one at a time. An initial pilot was run (not unlike a dress rehearsal) to determine the amount of time needed for each trial type so that an adequate amount of time was given to conduct the trials without interfering with the next scheduled participant.

5.5.2 Acquire participants

For the initial experiment, volunteer participants were acquired from the university population by posting flyers around the university describing the experiment and offering some money for the participants’ time. For this round of experiments, we got the participants one at a time by displaying a sign and asking library patrons. Once we had volunteers, and at the point where they came in for the experiment, they were be assigned to the experimental groups, described in Sections 5.2 and 5.3. All participants are anonymous in that no personal data including their actual name was collected with the exception of age, sex and whether they were able to use a traditional mouse and a head-operated mouse.

5.5.3 Interview participants

The interview consists of a few basic questions to determine the user’s ability to operate a standard mouse and a head mouse. Also during the interview, the participant is told what was going to happen in the experiment. Further, it establishes whether a participant is comfortable with going through with the experiment. The primary purpose of the interview is to inform potential participants about the experiment and also to gauge whether or not they would be willing to participate. Furthermore, any questions or concerns they have were addressed here as well. If a potential participant seemed willing and able, they were given a disclosure statement (see Figure 5.3) to read, date and sign. The disclosure statement puts into writing what was discussed during the interview and clearly states that participation is voluntary; that a participant may stop at any time; and describes the main steps of the experiment. The interview culminated with the administration of the pre-experiment questionnaire. In the actual experiments, no participant declined to participate.

5.5.4 Administer pre-experiment questionnaire

The purpose of the pre-experiment questionnaire is to record the information gathered from the interview, and to fully determine if a participant is able and willing to participate in the experiment. The form is also used to record information about the participant, like age, sex and group assignment. The form asks participants if they are comfortable using a traditional mouse and/or a head mouse (i.e., do they suffer any pain or discomfort in the hands, wrists, head or neck etc.). It asks the participants to rate their perceived ability with a traditional mouse as well as how well they think they could operate a head mouse. It also asks how many years they have used a standard computer mouse. The form is shown in Figure 5.4. In addition to Yes/No questions to determine if the participant will be comfortable using the two mouse devices, there are two “closed-ended with ordered choice,” [63] Likert-type [63, 64] questions as well. One asks the participant to gauge their skill with a traditional mouse and the other ask them to rate their physical coordination in general. As a participant finishes filling out the pre-experiment questionnaire, they will be assigned to a group.

5.5.5 Assign participants to groups

The experiments require four trials–one for each device type (traditional mouse and head mouse), and one for each path type (straight and curved). Each trial has four groups.

Participants are assigned to two different groups – one for the traditional mouse and one

for the head mouse. They are in the same group for both trials (i.e. straight and circular paths) of a device type. At the experiment site, two containers initially contained four cards. The containers were labeled corresponding to the device type. The cards correspond to each group, and were also be labeled for its container’s trials. As a participant came in, he/she randomly selected a card from each container, thus being assigned to a group for each device type. This assignment information was captured on the pre-experiment questionnaire and the collected data files were named accordingly. When the fourth participant selected the only remaining card from the containers, all the cards were reshuffled and put back into their corresponding containers for the next set of participants. After a participant had been assigned to a group, the experiment was run.

5.5.6 Training

The participants who are assigned to a group that receives training for a device type will be trained in the following manner. In addition to the verbal instruction and description provided to all participants, those who are to be trained are told that they will receive a training phase and that it does not count as the actual test, but is used to get them acquainted with the device/environment. This phase consists of an extra trial for each tunnel type (i.e. straight and circular). This extra trial/training phase (indicated as ‘Time 2’ in Figure 5.1) is only given once to a participant without repeat. Therefore, the user may not be fully proficient with the device/environment before the actual test phase begins (indicated as ‘Time 2’ in Figure 5.1). Also the intervention is applied or not dependent on the group assignment so that the intervention is the same in the training phase as it is in the regular phase. Data, identical to what is collected in a regular trial is also collected in the training phase. However, the data are labeled and saved as training data so that it may

be analyzed later as such. It is very probable that a participant may receive training on one device type and not the other or even training on both or neither depending on which groups they are assigned to for the two device types.

5.5.7 Run experiment

Depending on which groups the participant had been assigned, the trials were run as described in Sections 5.2 and 5.3. For each task (i.e. a line in Table 5.2 for a group), data files were named and stored for the participant, anonymously identifying the participant as a member of their assigned group. After the participant was finished with the experiment, they were asked to fill out a post-experiment questionnaire.

5.5.8 Administer post-experiment questionnaire

The purpose of the post-experiment questionnaire was to capture the opinions of the participants about the experiment and perhaps ways they would suggest to improve it and any and all thoughts they may have. The form consists of five “close-ended ordered” [63] Likert-type [63, 64] questions which are set to gauge the participants’ opinion of using the devices for the experiment. The form also contains two “open-ended” [63] question which are meant to capture participants’ overall attitude about the experiment and to give them a space to offer suggestions for improvement. At this point, the participant was thanked and paid for their participation. The post-experiment form is shown in Figure 5.5