# Shared Flashcard Set

## Details

SAFMED research methods terms
Research method terms
40
Psychology
01/13/2022

Term
 Central Tendency
Definition
 a genetic term describing the centre of a frequency disribution of observations measured by mean, median and mode
Term
 Confounding variable
Definition
 A variable that may or may not have been measured, other than the independent variable which influences the outcome of the dependent variable
Term
 Content validity
Definition
 Evidence that the content of a test corresponds to the content of the construct it was designed to cover
Term
 Correlation co-efficient
Definition
 A measure of strength and direction of the association between two variables.
Term
 Raw data
Definition
 A set of data that is yet to be screened for analysis
Term
 Repeated measure/within a subject t-test
Definition
 A test using the t-statistic that establishes whether two means collected from the same sample differ significantly
Term
 Independent sample between subjects t test
Definition
 A test using the t statistic that establishes whether two means cllected from independent samples differ significantly
Term
 Ecological validity
Definition
 refers to how the results produced from a study can be applied and generalised to real-life conditions
Term
 Experimental hypothesis
Definition
 the prediction that there will be an effect. The experiment manipulation of one variable will have some effect on the dependent variable or that certain varibles will relate to each other
Term
 Null hypothesis
Definition
 The reverse of the experimental hypothesis- that there will be no effect from your experimental manipulation, or that certain variables are not related.
Term
 Fit
Definition
 The degree to which a statistical model is an accurate representation of the observed data.Basic models- mean median mode. Complex models- correlation, t-test.
Term
 Frequency disribution
Definition
 A graph plotting values of observations on the Y axis, and the frequency with which those values occur on the X axis, commonly called a histogram. Used to assess the distribution of data.
Term
 Homogenity of variance
Definition
 An assumption of parametric testing in between-group designs, where the variance of one variable is stable at all levels of another variable.
Term
 Hypothesis
Definition
 A prediction about the state of the world
Term
 Independent design
Definition
 An experimental design in which different treatment conditions use different participants, resulting in independent data.
Term
 Repeated measures design
Definition
 An experimental design in which different treatment conditions use the same participants, resulting in related or repeated data.
Term
 Interval data
Definition
 Data measures on a scale along which all intervals are equal, for example, pain ratings on a scale of 1 to 10.
Term
 Ratio data
Definition
 Interval data, with the additional property that ratios are meaningful. For example, when assessing pain on a scale of 1 to 10, for the data to be considered ratio level, a score of 4 should genuinely represent twice as much pain as a score of 2.
Term
 Nominal data
Definition
 Data where numbers represent categories or names
Term
 Ordinal data
Definition
 Data that tell us not only that something occurred, but the order in which it occurred. Examples include data presented as ranks, for example, placements on participants in a race.
Term
 Kurtosis
Definition
 measure the degree to which scores cluster at the tails of a frequency distribution. Positive kurtosis- too many scores in the tail, resulting in a peaked curve.Negative Kurtosis- too few scores in the tail, resulting in a flattened curve
Term
 Likelihood
Definition
 the probability of obtaining a set of observations given the parameters of a model fitted to those observations
Term
 Mann Whitney Test
Definition
 a non-parametric test that examines the difference between two independent samples. The non-parametric version of a t-test
Term
 Mean
Definition
 A simple statistical model on the center of a distribution of scores; a hypothetical estimate of a ‘typical’ score, calculated by summing the observed scores and dividing by the number of observations (n).
Term
 Median
Definition
 The middle score of a test of ordered observations
Term
 Mode
Definition
 The most frequently occurring score
Term
 Non-parametric test
Definition
 A family of statistical tests that do not rely on the restrictive assumptions for parametric tests. In particular, they do not assume sampling disribution is normal. Normally considered less powerful.
Term
 Parametric test
Definition
 A family of statistical tests that require data to meet most assumptions. In particular around the distribution of data and the inter-relation between variable levels. The basic assumptions are: data normally disributed, homogenecity of variance, interval or ratio data, independence of scores.
Term
 Population
Definition
 In statistical terms, this refers to the group from which we draw a sample, and to which we want to generalise results.
Term
 Qualitative methods
Definition
 Extrapolating evidence for a theory from what people say and write (in contrast to quantitative methods).
Term
 Quantitative methods
Definition
 Inferring evidence for a theory through measurement of variables that produce numeric outcomes (in contrast to qualitative methods).
Term
 Quartiles
Definition
 A generic term for the three values that cut an ordered data set into four equal parts. The three sections are known as the lower, middle, and upper quartiles. The space between the lower and upper quartiles is known as the inter-quartile range.
Term
 Sample
Definition
 a smaller collection of units from a population, used to determine truths about population. (how a certain population behaves under certain conditions)
Term
 Standard deviation
Definition
 An estimate of the average spread and variability in set of data, measures in the same unit as original data. It is the square root of the variance
Term
 Skew
Definition
 A measure of the symmetry of a distribution, with a skew of 0 representing perfect symmetry. When scores are clustered at the lower end of the distribution, the skew is positive. When scores are clustered at the higher end of the higher end of the distribution, the skew is negative.
Term
 Test statistic
Definition
 A statistic for which we know how frequently different values occur in random samples. The observed value of such a statistic is usually used to test a hypothesis.
Term
 Validity
Definition
 Evidence that a study allows correct inferences about the question it was designed to answer, or that a test measures what is set out to measure.
Term
 Variance
Definition
 An estimate of the average variability of a set of dT. It is the sum of the squares divided by the number of values on which the sum of the square is based, minus 1.
Term
 Wilcox's signed-rank test.
Definition
 A non-parametric test that looks for the differences between a related t-test.
Term
 Z-score
Definition
 The value of an observation expressed in standard deviation units, calculated by taking the observed score and subtracting the sample mean, then dividing the result by the standard deviation of all observations. Z-scores can be used to assess the likelihood of obtaining certain scores on a measure.
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