UNIT 0 research methods

case study

study of one individual in great detail

confounding variable

a factor other than the independent variable that might produce an effect in an experiment

control group

In an experiment, the group that is not exposed to the treatment, serves as a comparison

correlation

A measure of the extent to which two factors vary together, how well either factor predicts the other.

correlation coefficient

a statistical index of the relationship between two things (from -1 to +1)

critical thinking

comparing what you already know with the information you are given in order to decide whether you agree with it

debriefing

the ethical principle in which participants must be fully informed of the nature of the study after participating in research

dependent variable

The outcome factor; the variable that may change in response to manipulations of the independent variable.

descriptive statistics

numerical data used to measure and describe characteristics of groups. Includes measures of central tendency and measures of variation.

double blind procedure

an experimental procedure in which both the research participants and the research staff are not aware whether the research participants have received the treatment or a placebo.

experiment

A research method which manipulates one or more factors to observe the effect, can be generalized

experimental group

In an experiment, the group that is exposed to the treatment

experimenter bias

a phenomenon that occurs when a researcher's expectations or preferences about the outcome of a study influence the results

falsifiability

if we claim something is scientifically true, we must be able to specify what evidence it would take to prove it wrong

hindsight bias

the tendency to believe, after learning an outcome, that one would have foreseen it 'i knew it all along'

histogram

a bar graph depicting a frequency distribution

hypothesis

An educated guess

illusory correlation

the perception of a relationship where none exists

independent variable

The experimental factor that is manipulated; the variable whose effect is being studied.

inferential statistics

numerical methods used to determine whether research data support a hypothesis or whether results were due to chance

informed consent

an ethical principle that research participants be told enough to enable them to choose whether they wish to participate

mean

the average of a distribution, obtained by adding the scores and then dividing by the number of scores

median

the middle score in a distribution when organized in order

meta-analysis

a "study of studies" that combines the findings of multiple studies to arrive at a conclusion

mode

the most frequently occurring score(s) in a distribution

naturalistic observation

observing and recording behavior in naturally occurring situations

normal curve

the symmetrical bell-shaped curve that describes distribution. Most scores fall near the average, and fewer and fewer scores lie near the extremes.

operational definitions

a statement of the procedures used to define research variables

peer reviews

The evaluation of scientific, academic, or professional work by others in the same field to ensure its quality and validity

percentile rank

the percentage of scores below a specific score in a distribution of scores

placebo

something which has a positive mental effect, but no physical effect

placebo effect

experimental results caused by expectations alone; any effect on behavior caused by the administration of an placebo

qualitative research

research focused on opinions and non numerical data

quantitative research

research that collects and reports data in numerical form

random assignment

assigning participants to experimental and control conditions by chance

random sample

a sample that fairly represents a population because each member has an equal chance of getting chosen for an experiment

range

the difference between the highest and lowest scores in a distribution

sampling bias

a flawed sampling process that produces an unrepresentative sample

scatter plot

A graph with points plotted to show a possible relationship between two sets of data.

self report bias

bias when people report their own behavior inaccurately

single blind procedure

research design in which participants don't know whether they are in the experimental or control group

skewed distribution

a representation of scores that lack symmetry around their average value

social desirability bias

A tendency to give socially approved answers to questions

standard deviation

a computed measure of how much scores vary around the mean score

statistical significance

a statistical statement of how likely it is that an obtained result occurred by chance

survey

a qualitative method used to record opinions

theory

A hypothesis that has been tested with a significant amount of data

validity

the extent to which a test measures or predicts what it is supposed to

variable

A factor that can change in an experiment