'Before you begin' quiz (Year 1 recap) Flashcards
What is the purpose of the ‘control’ condition?
To allow psychologists to make inferences about a cause.
What is a t- statistic?
The ratio of systematic : unsystematic variation
What is standard deviation?
The measure of dispersion of scores around the mean.
What does a small standard deviation represent?
All data points are close to the mean, therefore the mean is a ‘good fit’ of the data.
What does a large standard deviation represent?
All data points are very spread around the mean, therefore the mean is not a ‘good fit’ of the data.
What does a significant test statistic tell us?
The test statistic is larger than we would expect if there was no effect in population.
What does a positive correlation represent?
As one variable increases, the other increases too.
What does a negative correlation represent?
As one variable increases, the other decreases.
What is a Type-1 error?
We conclude there is an effect when in fact there is not.
What is a Type-2 error?
We conclude there is not an effect when in fact there is.
What is standard error?
- The standard deviation of sample means.
- Measure of how representative samples parameters are of the population.
- Computed from known sample stats.
- Provides an unbiased estimate of standard deviation.
Interpreting SPSS: What do we do if the Levene’s test is significant?
Read data from the ‘equal variances not assumed’ row.
What does positively skewed data look like on a graph?
Frequent scores clustered towards the lower end of the graph.
What does negatively skewed data look like on a graph?
Frequent scores clustered towards the higher end of the graph.
What does normally distributed data look like on a graph?
A bell curve.
