PSY 2317 UOHD Psychology & Additional Statistic Repeated Measures T Test Project

I’m working on a statistics multi-part question and need guidance to help me learn.

Example of a repeated measures t test

First, as an example of how to conduct a repeated measures t test, we’ll use the data from Example 11.2. You can see the raw data at the bottom of p. 367. These data are in the Example11-2.csv file.

(1) Download Example11-2.csv and open it in Jamovi.

(2) Be sure the measure type and data type are correct for the variables.

(3) From the T-Tests menu select Paired Samples T-Test.

(4) Move below_avg into the Variables box and then move above_avg into the Variables box. Be sure to move them in that order so that in the Variables box below_avg comes before above_avg. For purposes of the analysis, the order doesn’t matter. But by keeping them in this order, we’re instructing Jamovi to derive the difference scores by subtracting the above_avg scores from the below_avg scores, which will give us the same results as those reported in the textbook.

(5) From the Tests menu select Student.

(6) From the Hypothesis menu select Measure 1 ? Measure 2. Notice that this is identical to the alternative hypothesis on p. 367 (H ₁: M _D ? 0), which states that the mean of the difference scores between the two sets of scores is not 0.

(7) From the Additional Statistics menu select Mean difference and, directly below it, Confidence interval and be sure 95 is the Confidence interval value.

(8) Also from the Additional Statistics menu select Effect Size, and Descriptives.

(9) Save your analysis as Example11-2.omv, to be submitted as part of this assignment.

If you did everything right, you should see that your results pretty closely match those reported in the textbook for mean difference, df, estimated standard error (called SE Difference in Jamovi), t, estimated Cohen’s d, and 95% CI.

Watching seagulls

Seagulls in urban areas are often considered a nuisance due to behaviors such as food-snatching. Goumas et al. (2019) wondered if gulls’ food snatching behavior is influenced by human cues such as direction of gaze. So they measured the approach times, in seconds, of gulls to a food source placed close to an experimenter who either (a) looked directly at the gull or (b) looked away. Only 26% of the gulls would touch the food, suggesting that food-snatching is probably only committed by a minority of gulls. But for gulls that did touch the food, the question was whether the time they took to approach the food was affected by whether the experimenter was looking at them or looking away from them.

A bag of chips was placed on a surface and the experimenter crouched nearby with eyes at the level where the gulls’ eyes would be. The chips were inside a sealed, transparent plastic bag weighed down with a 550 gram weight to prevent the gulls from eating the food. This was because if they were successful on the first trial, there might be order effects (as described on p. 377-378). The stopwatch was started when a gull landed and took its first step toward the chips and timing was stopped when the gull pecked at the bag.

A gull’s second trial was started 180 seconds after the first ended, to allow normal behavior to resume. Between trials the chips were hidden and the gull was tracked using peripheral vision. A gull’s second trial began when it landed near the chips for the second time. For half of the gulls the first trial was “looking at” and the second trial was “looking away.” These conditions were reversed for the other half of the gulls. (See Counterbalancing on p. 378).

The approach times for the “looking at” and “looking away” trials are contained in the Seagulls.csv data set. We can analyze these data using a repeated measures t test to investigate whether food-snatching gulls’ approach times are affected by the direction of a human’s gaze.

Goumas, M., Burns, I., Kelley, L., & Boogert, N. (2019, April 5). Herring gulls respond to human gaze direction. Biology Letters, 15, 20190405. http://dx.doi.org/10.1098/rsbl.2019.0405.

(1) Download Seagulls.csv, open it in Jamovi, and conduct a paired samples t test. In the Analysis panel, move At into the Variables box first and then move Away into the Variables box. All settings should be the same as for Example11-2.

(2) Save the Jamovi file as Ch11_YourLastName.omv and use it to answer the questions on the worksheet.

Instructions for submitting this assignment.

(1) Locate Example11-2.omv, Ch11_YourLastName.omv, and Ch11 Homework.docx where you saved them on your computer.

(2) Click the title of this assignment ( Ch11 Homework) to open the Upload Assignment page.

(3) In the ASSIGNMENT SUBMISSION section, attach Example11-2.omv, Ch11_YourLastName.omv, and the Ch11 Homework file. Click Submit.

(4) If you submit this assignment early enough, I might have time to provide feedback that you can use to improve it and possibly improve your grade. So soon after you submit it, return to this assignment to see if I’ve given you any feedback. Click the assignment title and on the Review Submission History page you’ll see the details of your prior submissions. To revise a prior submission, click Start New, download and revise, be sure to save it, and upload it as previously.