AP Psychology August 18th pg 6 Objective Opener: Caption this meme with a perspective Identify Operational definitions, Independent variables, and dependent variables by completing 5 problems independently. Understand the basics of psychological statistics by taking notes and completing an in depth analysis.

Review and Application (bottom pg 3) Operational Definitions 1-5 together 6-10 independent Identifying IV, DV and creating hypothesis

Statistics Notes pg 4

Statistics 3 Ms of Central Tendency 1 1 1 2 2 3 4 4 4 4 5 5 5 6 6 7 7 Mode: the most frequent score Example: 5 9 7 4 6 8 2 4 1 3 5 1 4 6 9 8 7 5 2 4 1 Ordered: 3 2 1 4 3 2 2 2 2 1 1 1 2 2 3 4 4 4 4 5 5 5 6 6 7 7 8 8 9 9 MODE

Statistics 3 Ms of Central Tendency MEDIAN MEDIAN Median: the the middle score of any ordered set of numbers Ex (odd # of scores): 3 8 11 11 12 13 24 35 46 Ex (even # of scores): 3 8 11 11 12 13 24 35 46 48 (12 + 13)/2 = 12.5 = median MEDIAN MEDIAN

Statistics 3 Ms of Central Tendency Mean: the arithmetic average of scores Mean = add their values and divide by the number of observations. If the n observations are x1, x2,…..xn1, their mean is: A simpler notation:

Mean, cont. Statistics Ex: 3 8 11 11 12 13 24 35 46 48 (3+8+11+11+12+13+24+35+46+48) 10 (211) 10 21.1

Measures of Variability: Range Statistics Measures of Variability: Range Range Range = (highest score – lowest score) Example: 5 9 7 4 6 8 2 4 1 3 5 1 4 6 9 8 7 5 2 4 1 RANGE: 9 – 1 = 8

The Ever Popular Living Histogram Activity The Ever Popular Living Histogram

4’6”- 4’7” 4’8”- 4’9” 4’10”- 4’11” 5’0” – 5’1” 5’2”- 5’3” 5’4”- 5’5” 5’6”- 5’7” 5’8” – 5’9” 5’10”- 5’11” 6’0” – 6’1” 6’2”- 6’3”

Measures of Variability: The Normal Curve #5 (Testing). Interpret the meaning of scores in terms of the normal curve.

Statistics

Statistics

Statistics

Statistics Inferential Stats

Central Limit Theorem: Larger Sample Size = More Normal Applet Central Limit Theorem: Larger Sample Size = More Normal

A Lesson in Correlation REPEAT AFTER ME: Correlation is NOT causation!

What is a correlation? Correlation shows how two variables relate together. It is often confused that correlation can show a cause Examples: ACT scores correlate to college success (or failure) Parents who have children before the age of 18 are more likely to have children who have children before the age of 18 Correlations may be influenced in either direction Example: Friends tend to dress and act the same. Is it because of how they dress that they are friends or is it that because they are friends they choose to dress and act similar? With Correlation, one can never tell. Graph showing illusory correlations

What does a correlation measure? Correlations measure the STRENGTH of a relationship Correlation coefficient (r value) Between 1.00 to zero to -1.00 The closer to 1.00 or -1.00, the stronger the relationship The closer to zero, the weaker the relationship. The +/- indicates the direction of the relationship Which of the following correlation coefficients represents the STRONGEST relationship? -.87 .64 -.32 .24 Which is the weakest?

What do correlations look like? Correlations are represented visually through scatter plots Scatter plot – a cluster of dots, with each dot showing the values of two variables Each dot in the instance above shows a husband’s age (x-axis) and his wife’s corresponding age (y-axis)

What types of correlations are there? Correlations are either positive or negative Zero correlation = no relationship exists – such as age and eye color Positive: As one variable increases, the other increases (and vice versa) Negative: As one variable increases, the other decreases (and vice versa) In math terms: positive correlation = direct relationship negative correlation = inverse relationship. Which correlation is positive, and which is negative in the examples above? Type of Correlation Change in variables Positive Increase, Increase Decrease, Decrease Negative Increase, Decrease Decrease, Increase

Why can’t correlation show cause-effect? Extraneous (or 3rd) variables – Sometimes a correlation does not exist at all but it appears that it does because of a third variable. There is a positive correlation between ice cream and murder rates Does that mean that ice cream causes murder? What does ice cream and murder have in common? Video Clip: Correlation vs. Causality (poor ice cream getting a bad rap)

Correlation Even correlations that are clearly not cause-and- effect relationships can be used for prediction. Ex: College entrance exams and freshman GPA. Ex: Shoe size and vocabulary size in elementary school children. Ex: Ice cream sales and the rate of violent crimes. Socrates “How many things there are that I do not want!” Socrates & Plato Mind and body separate (mind continues after death) Knowledge built in. (nature) Aristotle driven by data & observation over logic Knowledge comes from experience (nurture)

Statistical Significance A measure of the likelihood that a result is caused by chance. In an experiment, we want that likelihood to be low so we can conclude a cause-and-effect relationship exists between the IV and the DV. Socrates “How many things there are that I do not want!” Socrates & Plato Mind and body separate (mind continues after death) Knowledge built in. (nature) Aristotle driven by data & observation over logic Knowledge comes from experience (nurture)

The P-Value explained Take Notes on the video

Statistical Significance To say that the results of an experiment are statistically significant means that there is a small likelihood that the results were caused by chance; that is, a high likelihood they were caused by the IV. The threshold for statistical significance is no more than a 5% likelihood the results were caused by chance. We express this: p ≤ .05 Socrates “How many things there are that I do not want!” Socrates & Plato Mind and body separate (mind continues after death) Knowledge built in. (nature) Aristotle driven by data & observation over logic Knowledge comes from experience (nurture)

Ethics in Research #9. Identify how ethical issues inform and constrain research practices. #10. Describe how ethical and legal guidelines (e.g., those provided by the American Psychological Association, federal regulations, local institutional review boards) protect research participants and promote sound ethical practice.

Ethics APA Code of Ethics

Ethics Institutional Review Board (IRB)

Ethics Informed Consent

Ethics Protection from Harm

Ethics Confidentiality

Within Psychological Treatment: HIPPA Ethics Within Psychological Treatment: HIPPA

Debriefing Right to Withdrawal Ethics Debriefing Right to Withdrawal

Ethics Animal Rights

Putting it all together! Research and Statistics Assignment