CHAPTER 2 RESEARCH GOALS OF PSYCHOLGY Coke Experiment

CHAPTER 2 - RESEARCH GOALS OF PSYCHOLGY Coke Experiment 1. MEASURE AND DESCRIBE…How will I get my numbers? What measurement technique will I use? – What is your operational definition? 2. UNDERSTAND PREDICT…. Let’s do some reading and then make a hypothesis! 3. APPLICATION AND CONTROL…. what did I find after my research was done? Can I now apply those findings to help someone with their problems? Psychology is empirical! We must answer our questions by conducting observations! Psychology is a science!

Steps In A Scientific Investigation Psychology is empirical……. knowledge should be acquired through observation 1. 2. 3. 4. Direct Observation Questionnaire Interview Psychological test (personality tests) 5. Physiological test (blood pressure, heart rate) 6. Examine archival records (census, economic records)

The peer review process is so demanding , many top journals reject 90% of submitted articles! A journal is a periodical that publishes technical and scholarly material.

EXPERIMENTAL RESEARCH • The purpose of an experiment is to find out whether changes in one variable (variable X) cause changes in another variable(variable Y). • How does X affect Y • X= Independent variable • Y= Dependent variable • The independent variable is called independent because it is free to be varied by the experimenter. WE MANIPULATE THIS! • The dependent variable is called the dependent because it is thought to depend on manipulations of the independent variable. • • • Does temperature cause aggression in humans? IV- Temperature DV- Aggression

LET’S REVIEW 1. A researcher is interested in how heart rate and blood pressure affected by viewing a violent film sequence as opposed to a nonviolent film sequence. • IV- Film Violence (We are manipulating this) • DV- Heart rate and blood pressure ------------------------------------------2. An organizational psychologist develops a new training program to improve clerks courtesy to customers in a large chain of retail stores. She conducts an experiment to see whether the training program leads to reduction in the number of customer complaints. • IV- training program (training vs. no training) • DV- Number of customer complaints --------------------------------------- • 3. A social psychologist investigates the impact of group size on subjects’ conformity in response to group pressure. • • IV- Group size DV- Conformity

EXPERIMENTAL AND CONTROL GROUPS CONTROLLED EXPERIMENTS! • EXPERIMENTAL GROUP- RECEIVE THE TREATMENT • CONTROL GROUP- DO NOT RECEIVE THE TREATMENT. • EVERY EFFORT IS MADE TO ENSURE ALL OTHER CONDITIONS ARE HELD CONSTANT FOR BOTH GROUPS. THIS METHOD MAKES IT POSSIBLE FOR RESEARCHERS TO CONCLUDE THAT THE EXPERIMENTS RESULTS ARE CAUSED BY THE TREATMENT, NOT BY SOMETHING ELSE. Example: Do extracurricular activities at school improve grades? CONTROL: random group of students who do not participate EXPERIMENTAL: random group of students who do participate What should be constant in both groups? (Extraneous Variables- variables that may affect the experiment, other than the independent variable) Educational backgrounds, sex, age, IQ scores………. . Confounding of variables- when two variables are linked together in a way that makes it difficult to sort out their specific effects. Ex- You are testing theory misery loves company. You have a control group and an experimental group. BUT you notice that you never looked at the sociability (extraneous variable) of both groups. Therefore, you don’t know if sociability or anxiety is affecting your experiment.

Descriptive/Correlational Research I cannot control all the variables…. What do I do? Cause and Effect cannot be determined…. but patterns and associations can • Naturalistic Observation – Behavior is allowed to unfold naturally in its natural environment – Used a lot to study animal behavior – Disadvantage- Reactivity…. behavior is altered by the presence of the observer – Do slender people and heavy people eat their food differently? How could you observe this? – Heavy people do tend to eat somewhat more rapidly than slender people. Heavy people also chew less often and leave less food on their plates. • Case Studies – An in-depth investigation of an individual subject – In order to obtain information about the people being studied researchers may observe or speak with them, and find out more about their backgrounds and personal histories. – One case study does not provide much basis for deriving general laws of behavior. However, if you examine a series of case studies involving similar problems, you can look for threads of consistency that may yield general results – Some case studies focus on rare cases- Genie

• Surveys • Researchers use questionnaires or interviews to gather information about specific aspects of participants’ background, attitudes, beliefs and behavior. • Disadvantages: wishful thinking, memory lapses, poorly worded questions. Let’s Review! Are people’s attitudes about nuclear disarmament related to their social class or education? Survey: Obtain information about social class, education and attitudes about disarmament Do people who suffer from anxiety disorders share similar early childhood experiences? Case Study: Interview people with anxiety disorders, interview their parents, and examine their school records to look for similarities in childhood experiences. Do troops of baboons display territoriality---that is, do they mark off an area as their own and defend it from intrusion by other baboons? Naturalistic- observe baboons in their natural environment without interference

Can the presence of food related cues (delicious-looking desserts in advertisements, for example) cause an increase in the amount of food that people eat? Experimental: To demonstrate a casual relationship, you would have to conduct an experiment. You would manipulate the presence or absence of food-related cues in controlled circumstances where subjects had an opportunity to eat some food, and monitor the amount eaten.

STATISTICS AND RESEARCH Whether researchers use experimental or correlational methods, they need some way to make sense of their data…this is where Statistics comes in. Statistics- use of math to organize data. Descriptive Statistics: Provide overview of numerical data • Central Tendency: Mean, median and mode – • Why might the mean be misleading sometimes? Variability refers to how much the scores in a data set vary from each other and from the mean. – Standard Deviation is an index of the amount of variability in a set of data. Set A 35 34 33 37 38 40 36 33 34 30 There is a bigger spread of data in Set B Speed (miles per hour) Set B 21 37 50 28 42 37 39 25 23 48 35 -------mean--------35 2. 87 ------SD---------10. 39

Correlation does not equal Causation • Correlation measures how closely one thing is related to another • The stronger the correlation between two things, the more closely those two things are related. If variables X and Y are correlated, does X cause Y, does Y cause X, or does some hidden third variable Z, account for the changes in both X and Y? Positive Correlation: Variables co-vary in the same direction If your high school GPA is high then your college GPA is likely to be high OR If your high school GPA is low then your college GPA is likely to be low.

Negative Correlation: Two variables co-vary in the opposite direction There is a negative correlation between stress and health. As one goes up, the other goes down. Stress Health *A correlation coefficient can vary between 0 and -1. 00 if negative and 0 and 1. 00 if positive. A coefficient near 0 indicates no relationship between the variables. • The closer the correlation to -1. 00 or +1. 00 the stronger the relationship. • EX- a correlation of -. 60 reflects a stronger relationship than a correlation of +. 30. • The positive and negative symbols just show the direction of the relationship

INFERENTIAL STATISTICS • • • After researchers have summarized their data with descriptive statistics, they still need to decide whether their data supports their hypothesis. Working with laws of probability, researchers use inferential statistics to evaluate the possibility that their results might be due to the fluctuations of chance. Statistically significant……this exists when researchers come to the conclusion that the observed findings are not likely due to chance. Less than 5 chances in 100 (. 05) Ex- A computerized tutoring program (the independent variable) is designed to increase reading achievement (dependent variable). Our hypothesis is that the program participants (the experimental group) will score higher than the non-participants (the control group) on a standardized reading test given at the end of the school year. There were 60 subjects in each group. Here are the results: Control Group Experimental Group 6. 3 MEAN 6. 8 1. 4 SD 2. 4 It is true that the scores were better. BUT Are the observed difference enough to support our hypothesis?

FLAWS IN EVALUATING RESEARCH • • • POPULATION: The whole group you want to observe SAMPLE: Collection of subjects for observation…only part of the population SAMPLING BIAS: exists when a sample is not representative of the population. • PLACEBO EFFECTS occurs when participants’ expectations lead them to experience some change even though they receive empty, fake, or ineffectual treatment. • SOCIAL DESIRABILITY BIAS…People will give you the answers you want to hear. • EXPERIMENTER BIAS…. When researcher’s expectations about the outcome of a study influence the results obtained. We can fix this problem by doing double-blind studies •

• Can you deceive your participants to avoid biases? • Is animal research ethical?