Lecture 1: Introduction to Statistics

Question 1

Constructs

Answer 1

Abstract features of interest within a population (like short-term memory, intelligence or education)

Question 2

Variables

Answer 2

Mathematical placeholders that represent specific values associated with these constructs.

Question 3

4 kinds of measurement levels

Answer 3

Nominal, ordinal, interval and ratio.

Nominal: categories that differ in name only (e.g., male/female, majors)

Ordinal: categories with a meaningful order (e.g., bachelor year 1, 2 and 3)

Interval: meaningful intervals/distance between values, which allow for meaningful comparisons between values. (e.g., Celsius and Fahrenheit)

Ratio: have a meaningful zero-point, which allows for the computation of meaningful ratios between values (e.g., Kelvin: at 0 Kelvin, atoms stop moving: therefore, the zero is meaningful)

Question 4

Descriptive statistics

Answer 4

Involves summarising and describing the characteristics of a dataset

Question 5

Interferential statistics

Answer 5

Allow us to make educated guesses about a larger population based on a smaller sample

Question 6

Positive skewed distributions

Answer 6

The mode best represents the common value, followed by the median, while the mean is not very representative

Question 7

Symmetrical distributions

Answer 7

The mean, median and mode all represent the common value equally good

Question 8

Negative skewed distributions

Answer 8

The mean best represents the most common value, followed by the median, while the mode is not very representative

Question 9

Mode

Answer 9

Most frequent score

Question 10

Bivariate distributions

Answer 10

Describe the co-occurrence of values on 2 different variables

Question 11

Variance

Answer 11

The average squared distance of observations to the mean