levo

Cognitive Psychology

Measures of central tendency and dispersion

  • 3 things to know
  • Papers 1 and 3

Overview

Recall questions on choosing and calculating the mean, median and mode, the range, percentages, calculating and interpreting standard deviation, significant figures and order-of-magnitude checks, and normal, positively skewed and negatively skewed distributions.

What you need to know

Answer each one before you reveal it.

Your recallNot started
Key term

How is the median found when there is an even number of data points?

Key term

Why is standard deviation generally preferred over the range as a measure of dispersion?

Key term

Why might a researcher choose the median over the mean when summarising data?

Questions from this subtopic

Each one with the model answer underneath.

  1. 1

    Why might a researcher choose the median over the mean when summarising data?

    Model answer

    The median is less affected by extreme values or outliers, making it more representative of central tendency in skewed distributions.

  2. 2

    In what situation would the mode be the most appropriate measure of central tendency?

    Model answer

    The mode is most appropriate for categorical or nominal data, or when identifying the most common response is more meaningful than an average.

  3. 3

    What is the mean as a measure of central tendency?

    Model answer

    The mean is the arithmetic average of a data set, calculated by summing all values and dividing by the number of values.

  4. 4

    Describe how the mean is calculated.

    Model answer

    The mean is calculated by summing all values in the data set and dividing by the total number of values.

  5. 5

    What formula is used to calculate the mean?

    Model answer

    Mean = sum of all values ÷ number of values.

  6. 6

    Calculate the mean when sum of values = 470, number of values = 11.

    Model answer

    Mean = 470 ÷ 11 = 42.7.

Other ways to work this

The same content, four other ways.

What is inside Levo

Six ways to work the same material.

1Closed book
2Open book
3Closed book

The 3-step method, run for you

Answer cold, learn it, then prove it stuck. Levo tracks the jump between your first attempt and your last.

Social Psychology
Cognitive Psychology
Biological Psychology
Learning Theories

Cram a whole paper in one sitting

Sort every topic into what you know and what you do not, then drill only the weak ones.

The area.
septalfrontaltemporal

Blank Blitz makes facts automatic

Rapid timed gap-fills on the terms and numbers you need to recall without thinking.

AEvery score is in the hundreds (of the order of 10² ms).
BThe mean must therefore also be in the hundreds.
C30.1 is ten times too small.

Build It gets the exam shape right

Assemble a full-mark answer from its marking points, in the order an examiner wants them.

In Rutter's study of Romanian orphans, children adopted before 6 months showed normal development.
TrueFalse

Test It catches misconceptions

Spot the fault in a statement. The traps are the mistakes students actually make.

721941163128510

Brain Breaks between sessions

Short focus games to reset attention, so the next set lands better than the last.

Every question in Cognitive Psychology, on a schedule.

Attempt a question from memory, write the correct version, then attempt it again. Levo records the jump between your first attempt and your last, and brings each question back on the day you are due to forget it.

Or £46 a year, about £3.83 a month. Cancel anytime.