Research methods definitions Flashcards
Experimental
An independent variable is changed and the effect on the dependant variable is observed
Non experimental
No variables are changed, the relationship between them is observed
Hypothesis
A scientific prediction of the relationship between two variables
Independent variable
The changed variable
Dependent variable
The variable effected by the dependant variable
Controlled variables
Variables that are controlled so they don’t influence the results
Extraneous variables
Extraneous Variables are undesirable variables that influence the relationship between the variables that an experimenter is examining.
Confounding variables
Confounding variables are variables that the researcher failed to control, or eliminate, damaging the internal validity of an experiment.
Correlation
An association between two variables
Correlational studies
Observation of the association between two variables
Archival research
Analyzing studies conducted by other researchers or by looking at historical patient records
Case studies
One type of observational data collection technique in which one individual is studied in-depth in order to identify behavioral, emotional, and/or cognitive qualities that are universally true, on average, of others
Qualitative
Refers to a study in which the scientist collects non-numerical data
Quantitative
numerical type of data that can manipulated and presented in graph form
Subjective
Subjective tests are inventories which assess your personality or various abilities in a biased manner
Objective
Objective tests are inventories which assess your personality or various abilities in an unbiased manner.
Descriptive statistics
Descriptive statistics are used to describe the basic features of the data in a study. They provide simple summaries about the sample and the measures.
Mean
A measure of central tendency which is more commonly known as an “average.”
The average or mean is calculated by adding all scores and then dividing by the number of scores.
Mode
A measure of central tendency which is defined by the most common number in an array.
Median
A measure of central tendency that is defined as the midpoint in an array of numbers. If the array has an uneven number of scores, the midpoint is the average of the two numbers closest to the middle.
Range
A statistical measure of variance. It is calculated by subtracting the lowest score from the highest score and then adding one (i.e., range = (highest score - lowest score) +1).
Population
Everyone who could possibly be a participant in the study is part of the population
Sample
A relatively small number of participants drawn from a population
Representative
when your participants closely match the characteristics of the population, which helps you generalize your results from your small group of people to large groups of people
Random sampling
Everyone in the entire population has an equal chance of being selected.
Stratified sampling
The researcher identifies the different types of people that make up the target population and work out of the proportions needed for the sample to be representative
Opportunity sampling
Uses people from target population available at the time and willing to take part, based on convenience
Systematic sampling
Chooses subjects in a systematic way from the target population, like every nth person on a list of names
Probability
The expected relative frequency of a particular outcome.
Statistical significance
Technically, statistical significance is the probability of some result from a statistical test occurring by chance.
Most often, psychologists look for a probability of 5% or less that the results are do to chance
Standard deviation
Standard Deviation is a measure of variation (or variability) that indicates the typical distance between the scores of a distribution and the mean. Tells us the average amount by which each score differs from the mean.
Variance
Tells us how spread out the scores are around the mean.
Reliability
The extent to which a test in consistent in its results
Inter-rater reliability
The degree to which different raters give consistent estimates of the same phenomenon
Internal consistency
Within the test the results should be consistent
Test-rest reliability
If the test is taken more than once the results should be consistent
Validity
The extent to which a test measures what it intends to measure
Internal validity
The extent to which only the independent
