# 'Before you begin' quiz (Year 1 recap) Flashcards

1
Q

What is the purpose of the ‘control’ condition?

A

To allow psychologists to make inferences about a cause.

2
Q

What is a t- statistic?

A

The ratio of systematic : unsystematic variation

3
Q

What is standard deviation?

A

The measure of dispersion of scores around the mean.

4
Q

What does a small standard deviation represent?

A

All data points are close to the mean, therefore the mean is a ‘good fit’ of the data.

5
Q

What does a large standard deviation represent?

A

All data points are very spread around the mean, therefore the mean is not a ‘good fit’ of the data.

6
Q

What does a significant test statistic tell us?

A

The test statistic is larger than we would expect if there was no effect in population.

7
Q

What does a positive correlation represent?

A

As one variable increases, the other increases too.

8
Q

What does a negative correlation represent?

A

As one variable increases, the other decreases.

9
Q

What is a Type-1 error?

A

We conclude there is an effect when in fact there is not.

10
Q

What is a Type-2 error?

A

We conclude there is not an effect when in fact there is.

11
Q

What is standard error?

A
• 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.
12
Q

Interpreting SPSS: What do we do if the Levene’s test is significant?

A

Read data from the ‘equal variances not assumed’ row.

13
Q

What does positively skewed data look like on a graph?

A

Frequent scores clustered towards the lower end of the graph.

14
Q

What does negatively skewed data look like on a graph?

A

Frequent scores clustered towards the higher end of the graph.

15
Q

What does normally distributed data look like on a graph?

A

A bell curve.

16
Q

What does the null hypothesis state?

A

No correlation will be found.

17
Q

What does the experimental hypothesis state?

A

A correlation will be found.
One-tailed hypothesis: do not state direction.
Two-tailed hypothesis: state direction of the correlation.

18
Q

What are confidence intervals?

A
• Calculated for a given statistic.
• A range around said statistic which the true value lies in (ie. 95% confidence interval = 95 of 100 sample would contain true value).
19
Q

How do we calculate z-scores?

A

z = score - all scores / SD