CHAPTER 2 - RESEARCH IN PSYCHOLOGY
STATISTICAL APPENDIX

Critical Thinking - process of assessing claims and making judgments on the basis of well-supported evidence

* What am I being asked to believe or accept?

* What evidence is available to support this assertion?

* Are there alternative ways of interpreting the evidence?

* What additional evidence would help to evaluate the alternatives?

* What conclusions are most reasonable?


SCIENTIFIC METHOD

People are more likely to help someone in roadside distress on a crowded highway than a country back road.

1. Hypothesis – specific, testable proposition about a subject under study

2. Design plan

3. Collect data

4. Analyze and draw conclusions

5. Journal – wide audience, replication

* Operational definition – 


* Variables – specific factors or characteristics that are manipulated/measured


* Theory – integrated set of statements designed to account for, predict, and suggest ways of controlling certain phenomena - "tentative"

* Four scientific goals of psychology – 


RESEARCH METHODS (IN REVIEW P. 42)

* Naturalistic Observation – watch without interfering, natural setting


* Case Studies – any/all information (profile of an individual, group, situation)


* Surveys – questionnaires, interviews, representative


* Experiments – situations where researcher manipulates one variable and observes effect of manipulation on other variable


VARIABLES AND EXPERIMENTATION

* Independent variable –


* Dependent variable –


* Experimental group – 


* Control group – 



PARTICIPANT SELECTION - SAMPLING

* Random sample vs. biased sample – 




THE PERILS OF EXPECTATION

* Confounding variables – 


o Random variables –


o Experimenter bias – unintentional changes in results due to expectations

* Double blind design - 


o Participant expectations

* Placebo – 


* Random assignment –



STATISTICAL ANALYSIS - THE GOOD STUFF!

* Descriptive Statistics – numbers used to describe and present data set

o Measures of central tendency
       
* Mean – 
       
       
* Median –


* Mode –


o Measures of variability

* Range – difference between highest and lowest scores in data set

* Standard deviation – degree to which scores in a data set vary from one another





o Correlation – relationship among two or more variables

* Range from –1 to 1


* Direction -


* Magnitude - 


* Correlation coefficient – expressed as r 


* Correlation and causation – a slippery slope



* Inferential – mathematical procedures used to draw conclusions from data and to make inferences about what they mean; are results due to chance?

o Procedures

* t-test – compare means of _________________ groups

* ANOVA – compare the means of _____________________ groups

o Statistical significance – are the results due to something other than chance factors?


ETHICAL GUIDELINES OF PSYCHOLOGISTS

* Analyze and report research findings accurately and fairly

* Preserve welfare and dignity of participants

* Cannot bring harm to participants

* Informed consent prior to experiment

* Debrief participants and allow them to obtain results of study


ADDITIONAL LEARNING OBJECTIVES – CHAPTER 2

* Define behavioral genetics. (see Linkages:  Psychological Research and Behavioral Genetics)
* Explain how family, twin, and adoption studies help to establish the relative roles of genetic and environmental variables. (see Linkages:  Psychological Research and Behavioral Genetics)

ADDITIONAL LEARNING OBJECTIVES – BEHAVIORAL GENETICS APPENDIX (P. A-1)
*  Describe some of the misunderstandings about behavioral genetics. Define heritability. (see The Focus of Research in Behavioral Genetics)
*  Describe the results of research on genetic influences over the life span and the genetic influence of multiple traits. Discuss the studies of the genes responsible for Huntington’s and Alzheimer’s diseases. (see The Role of Genetic Factors in Psychology)
*  Discuss how nonshared environmental factors may explain differences between siblings. (see Behavioral Genetics and Environmental Influences)
* Discuss the influence of genetics on environmental events. (see Behavioral Genetics and Environmental Influences)
*  Define genotype and phenotype. (see The Biology of Genetics and Heredity)