PsyTeachR FQA Ch. 9

conservative analysis

A conservative test is one that is more likely to result in more false negatives - i.e. missed findings - than a test considered less conservative

positive relationship

a relationship between two variables where as one variable increases, the other variable also increases

multiple comparisons

An issue of running mutlitple tests which results in an increase in the false positive rate making it more likely that you will incorrectly reject the null hypothesis and accept the alternative hypothesis. The issue is resolved through correction for multiple comparisons

alternative hypothesis

the experimental hypothesis formed in Null Hypothesis Significance Testing and is the hypothesis that states that there will be a relationship between variables or an effect of one variable on the other

q q plot

A scatterplot created by plotting two sets of quantiles against each other, used to check if data come from a specified distribution

significant

The conclusion where the p-value is lower than the critical alpha and at which the null hypothesis is rejected

correlation

The relationship two vectors have to each other.

assumptions

requirements about your data and your design that must be held for your analysis to have meaning

inferential

Statistics that allow you to make predictions about or comparisons between data (e.g., t-value, F-value, rho)

negative relationship

a relationship between two variables where as one variable increases, the other variable also decreases

homoscedasticity

that the spread of data around the line of best fit is equal on both side along the length of the line

hypothesis

A proposed explanation made on the basis of limited evidence as a starting point for further investigation.

Pearson

a standardised measure of the linear relationship between two variables

Spearman

a standardised measure of the relationship between two variables that does not assume a linear relationship. Note that the relationship can be linear but it is not required.

alpha

The cutoff value for making a decision to reject the null hypothesis

Holm Bonferroni

A correction for multiple comparisons where an ordinal iterative approach is used comparing each individual test to an adjusted p-value based on the order of p-values. Generally said to be less conservative than Bonferroni

scatterplot

a visualisation where each individual data point shows the value of an observation on twi variables.

null hypothesis

the defauly hypothesis in Null Hypothesis Significance Testing and is the hypothesis that states that there will be no effect or relationship in your study.

residual

Defined as the deviation of an observation from a model's expected value.

normal distribution

A symmetric distribution of data where values near the centre are most probable.

non significant

The conclusion where the p-value is greater than the critical alpha and at which the null hypothesis is retained

Bonferroni

A correction for multiple comparisons where the accepted alpha level is adjusted by dividing it by the number of comparisons made

variable

an aspect about your sample or population that can be measured

line of best fit

otherwise known as the regression line, it is the line drawn between data points in a scatterplot that best divides the data in half. It is in fact a prediction of where data would fall for a given relationship strength and direction

The end!