Test report overview and findings

¶ … Power Supply was written as an introduction to the subject and as a means to provide valuable safety information to the public. The paper provides an overview of the various parts of a power supply and how they work together. The three main parts of a power supply include input, processing, and output. Input is usually AC power; processing includes an AC input board, five separate DC power supplies, and a 12 volt source of power; and output is DC power. Also, the author discusses how to assemble a power supply including what tools are required. The tools required to assemble the power supply include several screwdrivers, a soldering iron, pliers and wire cutters. Specific parts needed to assemble the power supply are listed. Graphics are provided to illustrate the process of assembling the power supply. The intended target audience includes new or student technicians who are learning how to assemble power supplies. A pre-test questionnaire assesses the reader's familiarity with power supplies and his or her comfort level using the required tools. Also, the questions ask the reader about their level of familiarity with AC/DC power and working with electricity in general.

To determine the overall effectiveness of Things You Should Know about a Power Supply, I performed two user tests. Users were asked to follow my guide while assembling a power supply. Because the information contained in Things You Should Know about a Power Supply is basic, I refined the report into the following sub-sections: Objectives, Methods, Results, and Recommendations.

Objectives

First, I expect my users to become more familiar with AC/DC power, become more familiar with the role a power supply plays in electronic devices, and also to be able to assemble a basic power supply. Therefore, the main objectives of Things You Should Know about a Power Supply are as follows:

Attitudinal Objectives

Increased familiarity with AC/DC power

Increased familiarity with the form and function of a power supply

Increased understanding of how power supplies work in electronic devices

Knowledge of how to assemble a basic power supply

Test Objectives

Identify parts of a power supply

Assemble a power supply

Methods

To test the effectiveness of my document, Things You Should Know about a Power Supply, I conducted two performance tests and issued questionnaires before and after. I also went over the document thoroughly to correct errors or stylistic elements to help improve the report.

Procedure issued the two performance tests to two students who were taking an electronics course in school. Tests and questionnaires were issued to them simultaneously but they worked in separate rooms to avoid contaminating each others' progress. The students were both male and both were native English speakers. I selected native English speakers to avoid any problems associated with not being able to read the report. Tests and questionnaires were issued March 30, 2008 at 9 AM. First I handed the two students the pre-questionnaire. The questionnaire asked the following four questions:

What type of tools do you feel comfortable using?

What level of understanding do you have about AC/DC power?

Are you comfortable with dealing or working on electricity?

If so, what level of experience do you have?

The pre-questionnaire was designed specifically to ascertain the participants' level of experience to determine whether my report is accessible and useful to beginners. After the pre-questionnaire I gave the students a copy of Things You Should Know about a Power Supply. Then I offered them the supplies listed in the report to perform the test. All supplies were provided to me by the school. I was present at all times during the questionnaires and the physical test.

After the participants completed the assembly test, I issued a post-questionnaire to find out how they felt about the report and how helpful it was in guiding the assembly of a power supply. The post-questionnaire assessed the effectiveness of the assembly, asked if they understood the document and all the steps required to assemble the power supply, and also asked if the graphics were helpful. The post-questionnaire also asked the participants if they needed any additional information to make the document clearer or more useful.

Results/Discussion

Based on their responses to the pre-questionnaire both students indicated familiarity with all the tools required for the assembly including screwdrivers and wire cutters. Both participants also indicated some familiarity with AC/DC power, which they both claimed was from school. One of the two participants had about two years more schooling in electronics and so was more familiar than the other in assembling power supplies. Furthermore, both participants indicated they were comfortable dealing and working with electricity but neither had any professional experience, only some classroom experience.

The students were able to assemble the power supply after reading the document Things You Should Know about a Power Supply. However, one of the two students took a long time assembling it. That was the same student who indicated fewer years spent in the classroom. My observations showed that student was also hesitant about soldering and that part of the assembly took longer than the other. The more experienced participant completed the test in about twenty minutes. The other took almost forty minutes to complete the same task and at several points looked up at me or asked me a question.

Post-test questionnaire results revealed the following information:

Both participants assembled the power supply properly even though one took longer than the other to complete the task

The participant who took longer to complete the assembly indicated in the post-questionnaire that he did not understand the graphics because the photocopies were poor.

Post-questionnaire results also indicated that the document was relatively complete but both students mentioned needing better graphics and more safety information.