Me Myself and I Flashcards
What is the difference between samples and populations?
Samples are a subset of an entire population
What is sampling error?
Mistakes or random errors found within the sample making the sampling not representative of a population
How can sampling error arise?
Random variation/ misinterpretation/ sample size /
What is meant by a null hypothesise ?
A statement suggesting there is no relationship between the two variables.
What is meant by the alternative hypothesis?
Statement which opposes the null hypothesis and explains there is a relationship between two factors or variables.
What is the chi-squared test used for?
to find whether the difference between two variables is due to chance or is caused by something.
Describe the chi-squared test.
(sum of all observed values - sum of all expected values)^2 divided by expected
What is a biological parameter?
A way of measuring a biological component, e.g. Length/ mass…
What does the chi-squared test assume?
variables are categorised / observations are mutually exclusive and most expected values are greater than 5
What statistical test can be used for small samples in replacement of the chi-squared test?
Fisher test
What does the t-value tell us?
The size of difference between groups
What does the p-value tell us in a statistical test?
p<0.05 there is a statistical significance between the two values
What p-value do we need to reject the null hypothesis?
LOW P<0.05// As this tells us there is a significance between the data
What does the degrees of freedom tell us?
The number of independent variables involved in a test (1- number of variables)
What does a t-test measure?
If the mean of one group is statistically different from the mean of another group.
What does standard error/ deviation tell us?
The variation between calculated mean of population and the actual
What is the purpose of regression models?
To describe the relationship between a dependent and independent variable
What are residuals?
The differences between observed values and those predicted by the regression line (line of best fit)
What does the r^2 value tell us?
How ‘well’ the regression line represents the data
What does the 95% coefficient tell us?
you are 95% confident in your data set
What does a larger confidence interval suggest
There is a larger amount of uncertainty
What is meant by a multivariate linear model?
measures multiple variables, to predict outcomes
What is meant by longitudinal and cross-sectional data?
Longitudinal = data collected from following one individual over a period of time// cross -sectional= collected data from different individuals at one specific moment in time.
