R690 Fall 2012
45-minute Research Projects
Group 1
Your research project is to describe the R690 instructor’s office. In particular: What is unique about this office? What sets it apart from all else? Please do not look inside any file or desk drawers, play with the computer, or disturb any papers lying around. Just observe carefully. After recording your observations, interview the occupant, and ask questions about what is in the office and why it is organized as it is. What changed in terms of your interpretation of your findings, when comparing your initial observations to what you learned in the interview?
Group 2
Task 1. Your research project is to determine which coffee can you have been given. There are two cans. One of them contains 60 percent red cubes, and the other has 40 percent red cubes. Rules:
· No peeking inside the can.
· You can draw a random sample (blindly) of 10 cubes at a time.
· You can note the proportion of red cubes in the sample, after each draw.
· You must replace the 10 cubes sampled each time.
· Shake the can each time before you draw your sample.
· Take 10 samples of 10 cubes each.
You must decide which can it is and how much money you are willing to bet that you are right. What is the justification for your conclusion?
Task 2. Next, go to: https://www.indiana.edu/~tedfrick/decide/start.html . Label Alternative A as Hypothesis 1 and Alternative B as Hypothesis 2. For the minimum percent success if A is true enter 60, and for the maximum for B enter 40. For the error rates for false conclusions enter 5 for each error type (meaning 5 percent). Then click the “Continue…” button. Now conduct a sequential sampling experiment. You will be selecting 1 cube at a time, and then put it back in the can. If it is a red cube, enter a 1 in the success box. Otherwise enter a 1 in the failure box. Record the results after each update of the posterior probabilities. Continue sampling cubes one at a time and replacing them until a decision can be reached.
Is the decision the same as for Task 1?
Task 3. Repeat Task 2, but change the error rates from 5 percent to 1 percent. What do you conclude from all this?
Group 3
Your research project is to rapidly create a job aid (in about 20 minutes) for instructors who will use the computer presentation station in 2275 with the video projector. Then you need to conduct a formative evaluation (usability test) with someone representative of the target audience. See if she can connect a laptop computer to the presentation station and get it to display on the big projection screen. The IST administrative secretary will serve as a subject for your usability test. Is the job aid effective – i.e., can the target audience successfully use the 2275 presentation station? What is the evidence to support your conclusion? What criteria did you use to judge the effectiveness of the job aid? What is the justification for your criteria?
Group 4 – not needed this time…
Your research project is to identify probabilities of patterns of colors in cube strands. You will be given a large can with strands, each consisting of 3 colored cubes which are connected together. Like Group 2, you are not allowed to peek inside the can. You are to perform a series of sampling experiments, where one strand is chosen blindly each time, and then after observing the pattern of colors, the cube strand must be returned to the can. Each time, gently stir the cube strands (don’t shake the can as it may separate the strands), before having a different team member do the next sample. Try to collect at least 50 or possibly 100 samples of one strand each, selected at random, with replacement.
Answer the following questions:
1. What is the predominate combination of colors in each strand, not in any particular order? Estimate its relative frequency—i.e., the probability of selecting that color pattern (a number, which is a proportion, between zero and one).
2. What is or are the least likely color combinations in a strand. Again, estimate its or their relative frequency or frequencies.
3. Now estimate a conditional probability: If at least one of the cubes is White in any given strand (the condition or constraint), what is the likelihood (conditional probability) that one of the other cubes in the same strand is Red?
4. The head of a strand has no knob, whereas the tail of the strand has a protruding knob. If the head is Red (the condition or constraint), what is the conditional probability that the middle cube is Yellow? If the head is Red, what is the conditional probability that the tail is Blue.
You should do your tallies for each of the above questions, when you take a sample strand out of the can, before you put it back. Explain how you estimated each of the probabilities and conditional probabilities.