PSYC 3070 K
PSYC 3070 K
Descriptive Statistics:
Data Sets & HW Problems:
Read the following chapters and answer the suggested questions. Descriptive problem sets: (very important to get comfy with your calculator)
ch1: problems 3 and 5
ch2: problems 1, 2, 3, 5, and 7
ch5: problems 1, 2, 3, 4, 5, 9, and 11
ch6: problems 1, 2, 3, 4, 7, 9, 11, 13, 15, and 17
ch8: problems 1, 2, 3, 4, 5, 7, 9, 11
Lab work in SPSS and outside problems to solve to automate these new skills
Let's bring this file into SPSS
INtro to SPSS
how to use the database
labeling
how to change preferences
syntax on output
how to import
file formats
Descriptive Lab Examples
The Apathetic Interest Index had been given to 327 students at P.U. The data from this sample are ∑X = 3,531.6, ∑X2 = 41,702.31. Assuming this sample was drawn from a normally distributed population, use this information to solve the problems below. You should work all problems by yourself for experience.
1. What is the percentile rank of a student scoring 13.4?
2. What is the percentile rank of a student scoring 6.2?
3. How many students would score between 7.3 and 8.5?
4. What is the probability that a student will score 17.5 or higher?
5. What scores are so deviant that less than 2% of the population makes them?
We know that a reading test has a mean of 10 and a standard deviation of 2. Using the normal distribution, answer the following questions:
What is the percentile rank corresponding to a score of 11.2?
If we tested 1000 randomly selected students, how many would be expected to score 5 or lower?
What reading score corresponds to a percentile rank of 75%? 30%
What is the probability of a score of 13 or higher?
In an intro psych class, 83 students have taken a sociability rating scale. The possible ratings are from 1 to 7 with a low score indicating low sociability an a high score indicating high sociability. The average rating has been M=4.23, with SD=1.02. Using the normal curve table, answer the following questions:
What is the percentile rank of a student with a rating of 3.11?
How many of the 83 students had scores between 4.88 and 5.62?
What scores are so deviant that they occurred 1% or less of the time?
How many students had scores of 2.55 or less? 6.11 or more?
t-tests and Sampling Distribution of the Means:
Data Sets, Lab Work and HW Problems:
Read the following chapters and answer the suggested questions.
ch9: problems 1, 2, 3, 5, 6, 7, 9, 11, and 19
ch10: problems 1, 2, 3, 5, 9, 11, 13, 15
One sample t-tests & confidence intervals (Lab Directions)
t-test lab for independent and dependent samples (Lab Directions)
Directions for Hypothesis Testing Lab Work
Hypothesis testing readings to help orient you
Fisher, Sir Ronald A. (1956) [1935]. "Mathematics of a Lady Tasting Tea". in James Roy Newman. The World of Mathematics, volume 3.
20bits by Jesse Farmer (October 27th, 2008) Hypothesis Testing: The Basics This essay exams hypothesis testing using a coin toss.
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Extra Problem Sets:
Confidence Intervals:
Given M=100, SD=20, and N=25:
Find the 99%CI for mu.
If N=147, what is the 95%CI for mu?
Find the 99% and 95% CIs for each of the following samples:
M=15, N=17, SD=5
∑X=240, N=40, SE=1.6
N=170, ∑X=1445, ∑X2=12,343.25
One Sample t-test
The running time for 137 rats in a 6-foot runway is recorded. The data are ∑X=1,781 seconds, and ∑X2=25,345. Assume the mu=11.5 seconds, Test H0.
A company has developed a training procedure to improve SAT scores. Following training, 100 high school students take the SAT. The average math score is 517, with a SD=90. Assuming mu=500 for the math SAT, test teh null hypothesis. Did the training significantly improve scores? Set alpha at .05.
The enlarged liver sub-test of the college lifestyle exam yields mu = 49.2. The office of student affairs often gives this test to pledges to make sure they are not being hazed. The enlarged liver scores of 12 bothers from alpha beta something-or-other are listed below:
42, 76, 59, 62, 52, 57, 63, 50, 48, 72, 81, 39
Find:
the mean
variance
standard deviation
estimated standard error of the mean
Set alpha at .05 and answer the following question: Do these pledges being tested evidence a more enlarged liver based upon the sub-test scores than would be expected from the norms?
Now, what is the 99% confidence interval for mu?
Dr. Smith and some social psych students find that in a typical 15 minute car ride with a spouse, a person outputs 32.1 nods of the head and other signs that they are paying attention to the conversing partner. In a sample of 13 couples on the rocks, the average number or affirmative responses is 22.6, with s = 7.6
Does being in a troubled relationship reduce these cues?
What is the 99% C.I. for mu?
Extra Independent and Dependent t-tests
Correlation and Regression
y' = a + bx Lecture Slides - correlations and regression
Data Sets & Homework Problems:
read chapter 13, pages 293 - 325
solve the book problems: 1, 2, 3, 4, 5, 7, 10, 11
Lab Practice #2 with correlations
Extra Practice Problems:
Pearson Problems and Simple Regression
ANOVA
ANOVA lectures:
One-Way Independent Samples ANOVA lecture (between groups)
One-way Dependent Samples ANOVA lecture (within groups)
read chapter 11 pages 237-279 and chapter 12 pages 280-292 *Note we will only use Fisher's LSD as our post hoc test, so you may skim over Tukey's HSD sections in chapter 11 (so we are simplifying)
Solve book problems in chapter 11: 1, 3, 4, 5, 7, 9. Always perform an LSD post hoc if needed, ignore book directions.
Solve book problems in chapter 12: 1, 2, 3, 4, 5
Data Sets & Homework Problems:
How To SPSS:
Extra Practice Problems:
Sixteen elementary school students are randomly assigned to one of four groups. Each group solves a different kind of arithmetic problem: addition, subtraction, multiplication, or division. Each child solves 10 problems, and the average latency in seconds is recorded. Perform an overall test of significance.
Addition Subtraction Multiplication Division
2 5 5 5
2 6 5 8
4 7 8 10
4 6 6 9
An investigator is interested in the effect of level of illumination on the ability to see color. He randomly assigns 28 volunteers to one of four groups. Members of each group are given 12 trials on which they are asked to choose which of two different-colored objects has the highest degree of color saturation. Each group performs the task under different lighting conditions. The data (number correct) are given here. Did lighting affect the perception of color saturation?
Slightly Mod Very
Normal Dim Dim Dim
9 2 4 2
12 8 3 0
8 3 2 1
7 9 5 0
5 4 3 1
8 2 2 2
7 7 2 1
A child psychologist is interested in the course of development of object conservation in infants. The psychologist studies seven infants over a 6-month period. The infants are given 20 test trials at the ages of 9 months, 12 months, and 15 months. On each trial, an object is shown to the child and then is covered by a cloth. The child shows conservation if he or she looks for the object or becomes distressed when it is covered. The number of trials, out of 20, on which the child shows conservation is recorded. Perform the appropriate analysis; if significant, do all pairwise comparisons with the Fisher LSD test. Tell what your answers mean in the context of the problem.
Child 9 Months 12 Months 15 Months
A 0 3 17
B 2 4 17
C 3 6 16
D 1 2 14
E 0 1 19
F 4 9 2
G 4 3 20
A study was done to see whether the source of dietary fat affects visual discrimination. Rats were placed on one of four diets for 2 months: Diet 1 had 5% corn oil; Diet 2 was the same as Diet 1 with the addition of 20% safflower oil; Diet 3 was Diet 1 with 20% added coconut oil; Diet 4 was Diet 1 with 20% added olive oil. All the rats were trained on a simple visual discrimination task, and their errors before achieving a certain criterion were recorded. Test the data to see whether the different diets affected learning of the task.
Diet 1 Diet 2 Diet 3 Diet 4
13 10 7 14
20 20 17 19
31 34 11 27
18 27 23 31
11 7 14 15
11 27 13 21
11 10 26 14
12 12 23
12 32 4
12 11
In a study of dark adaptation, eight participants seated in an almost totally dark room were asked to determine visually the presence or absence of an object. All participants were given 10 trials after 1 minute of adaptation, after 15 minutes, and after 30 minutes. At each testing, the number of correct detections out of 10 trials was recorded. Perform an overall significance test, and tell what your conclusion means in the context of the problem.
1 Minute 15 Minutes 30 Minutes
2 6 6
0 2 4
4 7 9
3 5 6
6 8 10
0 2 4
2 5 1
3 5 8
Extra Problems, Variety of Designs
Chi Square and other nonparametric tests
Chi-square lectures:
Data Sets & Homework Problems:
Extra Practice Problems:
Extra work for outside and more lab based practice