INSTRUCTIONS FOR REGRESSION PROJECT -- WITH POINT VALUES
( 10 )[
] I. Obtain data and write the introduction to the project. The project consists of designing an experiment appropriate
for regression (linear and exponential bivariate), collecting data, performing the analysis, interpreting and
discussing results, and making predictions. You must generate your own data and not use already-existing
data.
( 0 ) [ ] A. At least ten data points must be used.
( 5 ) [ ] B. What is the project about? Describe the x and y variables, and the suspected relationship between them
(positive or negative correlation? linear or exponential?
( 5 ) [ ] C. Describe the experiment, including a clear and complete statement of what was done, and how x and y
were measured. The description must be complete enough to allow another researcher to replicate
(duplicate) the experiment to verify the results.
( 10 )[
] II. Graph the data -- graphs are already set up in the REG spreadsheet (see Part III)
( 2 ) [ ] A. Label and number the x and y axes -- figure out how to get the labels onto the graph.
( 2 ) [ ] B. Plot each data point.
( 6 ) [ ] C. Plot the linear and exponential regression lines; label them with their equations.
( 5 )[
] III. Use the regression spreadsheet program and include the printout in your report. Be sure that all parts of each
page are printed.
( 40 )[
] IV.
( 5 )[
( 5 )[
( 5 )[
(10) [
Interpret the computer printout.
] A. Explain the significance of the three squared-deviation totals in Table 3.
] B. Interpret the slope and intercept values in the linear model.
] C. Interpret the growth factor and intercept values in the exponential model.
] D. Give the results of hypothesis tests for the linear and exponential relationships between x and y. Include
statements of the null and two-sided alternate hypotheses, the table- and calculated-t's, and p-values.
(Note: Non-rejections of null hypotheses do not mean that your experiment failed. Learning that two
variables may not be related is just as important as learning that they are related.)
( 5 ) [ ] E. Perform whatever other analyses of the data that you feel may be useful in understanding the phenomena
studied in your experiment, and that may help in arriving at your final forecasts in section V.C. below.
(10) [ ] F. Discuss the results. What did you learn? Were there any surprises? How could the experiment be
improved? What suggestions or questions did the experiment raise for possible further research, etc.
( 25 )[
] V. Predictions.
(10) [ ] A. Choose two x-values for predictions. One x-value should be near the mean of the x's in the data set, and
the other should be near the lowest or highest x in the data set. Be sure that your chosen x-values are
included in the prediction tables at the end of the computer printout. On the linear and exponential graph
pages, draw vertical lines at the selected x-values, intersecting the prediction line and the upper and lower
95% confidence limits.
( 5 ) [ ] B. Report the two (lin & exp) predictions for each x, and the 95% confidence intervals. Use the sizes of the
intervals to evaluate the usefulness of the linear and exponential models.
(10) [ ] C. In light of your experience with this experiment, make a final forecast, with rationale, for each of the same
two x-values. (You might use the linear prediction, the exponential prediction, something in between, or
whatever you feel will be the best forecast.) Imagine that you are being paid for your forecast, and that
your reputation depends on its quality and the rationale that you provide for your client. (If your forecast
turns out to be inaccurate, it helps if you can show your client that you used a reasonable approach in
arriving at your predictions.)
( 5 )[
] VI. Summarize your results in one concise paragraph. (Such an "abstract" is usually placed at the beginning of a
research report.)
( 5 )[
] VII. General: Reports must be typed or computer-printed; grammar and spelling should be correct; neatness and
good form are important; label report sections as indicated above.
EXPERIMENTS INVOLVING ALCOHOLIC BEVERAGE CONSUMPTION, OR ANY OTHER DANGEROUS AND/OR
ILLEGAL ACTIVITY WILL NOT BE ACCEPTED. Experiments involving exercise and human subjects are not permitted
unless the subjects are athletes and the exercise is a type that they are already accustomed to doing. THE MAXIMUM
GROUP SIZE IS THREE. Due dates will be announced for: identification of group membership; project topic (general
description and x- and y-variables); report submission. One-point-per-day penalty for late compliance with deadlines.
Projects will not be returned, so make a copy for yourself if you so desire.