psych unit 0 second half

quantitative research

 uses numerical data to represent degrees of a variable. A research method that relies on quantifiable, numerical data.

qualitative research

A research method that relies on in-depth, narrative data that are not translated into numbers.

informed consent

letting potential participants know enough about a study to let them choose if they wish to partake or not.

debrief

the post-experimental explanation of a study, including its purpose and any deceptions, to its participants.

descriptive statistics

numerical data used to measure and describe characteristics of groups; include measures of central tendency and measures of variation. Summarizes data

histogram

a bar graph depicting a frequency distribution

mode

most frequently occurring score(s)

mean

Total sum of all the scores divided by the number of scores.

median

the middle score. If seen on as a number line the median would be the score in the center, half the scores above and half the scores below.

percentile rank

the percentage of scores that are less than a given score.

skewed distribution

a representation of scores that lack symmetry around their average value.

rank

the difference between the highest and lowest cores in a distribution

standard deviation

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

normal curve

a symmetrical, bell-shaped curve that describes the distribution of many types of data; most scores fall near the mean and fewer and fewer scores lie near the extremes.

inferential statistics

numerical data that allow one to generalize— to infer from sample data the probability of something being true of a population.

statistical significance

a statistical statement of how likely it is that a result (such as a difference between samples) occurred by chance, assuming there is no difference between the populations being studied.

meta-analysis

 a statistical procedure for analyzing the results of multiple studies to reach an overall conclusion.

effect size

 the strength of the relationship between two variables. The larger the effect size, the more one variable can be explained by the other.

generaliability principles (3)

1. Representative samples are better than biased (unrepresentative) samples.

2. Bigger samples are better than smaller ones.

3. More estimates are better than fewer estimates.