Research Methods Flashcards
correlation
a measure of how strongly 2 or more variables are related to each other
is correlation more ethical
yes because nothing is manipulated
positive correlation
as one variable increases, so does the other
negative correlation
as one variable increases the other decreases
correlation coefficient
measures the strength of relationship between -1 and +1
2 types of hypothesis
null
alternate (one or two-tailed)
two-tailed hypothesis
“there is a correlation between”
either positive or negative correlation
one-tailed hypothesis
“there is a positive correlation” or “there is a negative correlation”
null hypothesis
“there is no correlation between”
nominal data
data put into named categories
ordinal data
data put into rank order from lowest to highest
interval data
data is taken using the same unit of measure throughout the range
discrete data
data that can only take a certain individual value
continuous data
data that can have any number value in a certain range
assumptions of parametric tests
populations drawn from should be normally distributed, variances of populations should be equal, at least interval/ratio data, no extreme scores
why non-parametric tests are used
when assumptions of parametric tests can’t be fulfilled, when distributions are non-normal
independent variable
the factor you change
dependent variable
the result when affected by the independent variable
experiments designs
independent groups, repeated measures, matched groups, quasi
independent groups
when there are groups of different participants being tested by the same test
repeated measures
the groups of participants are the same but given different tests
matched groups
the different groups are matched for intelligence/ability/skill etc.
quasi
an experiment with independent variables that are not open to manipulation therefore, have naturally occurring groups
if the standard deviation is large
the values are widely distributed and scores can occur a long way from the mean
