Unit 1 Part 2: Research Methods

Empirical Investigation

an approach to research that relies on sensory experience and observation as research data

Scientific method

Five step process for empirical investigation of a hypothesis under condtions designed to control biases and subjective judgement

Hypothesis

A statement predicting the outcome of a scientific study

Falsifibility

the possibility that the hypothesis can be disproven

Operational Definition

exact procedures used in establishing experimental conditions and measurement of results

Independent Variable

the variable manipulated by the experimenter

Experimental Group

the group that receives the treatment

Random Sample

everyone from the population has an equal chance of being chosen for the study

Random assingment

once chosen, those in the sample have an equal chance to be in the experimental or control group

Confounding Variable

other variables that could possibly affect the experiment

Replication

making sure that their work can withstand the scrutiny of the scientific community

Convienience Sampling

quick and easy, but flawed due to bias; not random or representative

Hawthorne Effect

just the fact that you know you are in an experiment can cause deception

Corretional studies

relationship between 2 variables

Postive correlation

both increase/decrease

Negative correlation

one increases, other decreases

Illusory Correlation

perceiving a relationship when there is nothing there

Third variable problem

relationship of two variables might be because of some other third varibale not related to the other two

Qualitative

spoken answers/interviews , Naturalistic Observation, Case Studies

Quantitative

Raw numbers, Experiment, Correlation

Social Desirability Bias

answer questions based on how you think is socially desirable

Expectancy Bias

you expect something to be there and see the results even though they are not there

Self-fufilling prophecy

belief that results in behavior that makes that belief come true

Single blind study

participants dont know which group they are in

Double blind study

both participants and researchers dont know which groups they are in

IRB

Institutional Review Board needs to review ethical guidlines of experiment

Normal Distribution

mode, median, and mean are all the same

bell curve

68% in 1 SD
95% in 2 SD
99.7% in 3 SD

Postitively skewed distribution

mostly low test scores and one high outlier

Negative skew

mostly high test scores and one low

Z score

measures the distance of one score from the mean

positive z score

number is above the mean

negative z score

number is below the mean

Statistical Significance

knowing results did not happen by chance P<0.05