Transcript Unit 2 bio evidence of practice

Unit 2
The Biological Approach
Evidence of Practice
Lesson outcomes
• By the end of the lesson you will have
completed the biological approach practical
• You will have practised using psychological
terminology
• You will be ready to write up the practical over
Easter
Practical: A test of difference
• You need to be able to devise and conduct one
practical, which must be a test of difference
collecting ordinal or interval/ratio data using an
independent groups design.
• You should be able to carry out a Mann-Whitney
U test and interpret the findings.
• You should be able to write up the hypothesis,
results and analysis of the study, using an
appropriate graph and a table of the results, and
to draw conclusions.
You must be able to...
Identify, describe and apply the following terms:
i alternative, experimental and null hypothesis
ii one or two tailed with regard to tests
iii levels of significance (eg p= 0.01, 0.05)
iv Mann-Whitney U, - critical value and observed value
v dependent variable (DV) and independent variable (IV) in experiments
vi the use of control groups
vii experimental procedures including allocating groups to conditions (e.g.
randomising) and sampling
vii levels of measurement.
Practical: A test of difference
Brain text book
Read pages 244-254 in AS
Psychology
Spatial Intelligence
Spatial intelligence is the ability to comprehend
three-dimensional images and shapes. Visual spatial
intelligence activities include putting together a
puzzle or sculpture. This type of intelligence stems
from the left side of the brain, and injuries or
strokes to this part of the brain may diminish this
ability.
Spatial intelligences rely largely on people’s abilities
to picture the shapes and spaces of objects in their
minds; it is the ability to retain the form of
something in the mind’s eye.
The highest visual spatial intelligences result
from unique abilities to take up different
positions in the mind’s eye, such as a fly on the
wall or a person standing behind a curtain.
Those who have high spatial intelligences
usually do best in technical or science fields.
Architects, navigators, chess players, physicists
and designers are careers that people with high
spatial intelligences are often drawn to.
Males are believed to have better spatial skills
than females due to the way their brains are
lateralised.
Conduct practical
Lets do it
Procedure - Methodoloy
• Opportunity sample – AS psychology students
• verbal consent obtained
• Situational variables and ppt variables were
controlled
• Quasi/natural experiment
• H1 – Males will achieve higher scores out of
33 on the psychometric spatial skills test than
females
• The experimental design was independent measures
• Standardised instruction were used.
• Ppts had 10 minutes – (timed with a stop watch) to
complete the test.
• The answer sheets were marked out of 33 and scores
were collected.
• The mean and median (measures of central tendency)
were calculated and put into a table.
• The means were then presented as a bar chart.
• The range was calculated – the difference between the
highest and lowest score for each group of ppts (males
group and female group)
• The range was calculated – this is the
difference between the highest and lowest
score for each group. This is called the
measure of dispersion.
• An inferential statistical test was then
performed on the data. It was called the
Mann-Whitney U test
• This was the appropriate test as we were
conducting an experiment. The level of data
was ordinal (you can rank the scores from
lowest to highest), and it was an independent
measures design
The Mann-Whitney U test
Here is the formula
What were the results of your analysis from your Mann-Whitney U calculation?
Ua = ?
Ub= ?
The observed value of U is the Lowest number value of U (either Ua or Ub).
The Critical value for significance at 0.05 is the value we get from looking at
the table.
If your observed value (the one we calculated) is lower than the critical value
it means your results are significant at 0.05 or 5%. P≤0.05
Meaning: The probability of the results being a fluke (down to chance) is
less than 5%
If your calculated U is higher than the critical value of U your results are not
significant at 0.05 or 5%. P≥0.05.
Meaning: The probability of the results being a fluke (down to chance) is
more than 5%
• So we were required to use the lowest of the
two values of U.
• Ua was…..
• Ub was……
• So the observed value we used was ………….
• The critical value from the Mann-Whitney U
table was …………………….
• If the result was significant we could reject the
null hypothesis and accept the experimental
hypothesis.
• If it was not significant we had to reject the
experimental hypothesis and accept the null
hypothesis
• The statement of significance was either
P≤0.05 or P≥0.05
If your results are NOT SIGNIFICANT then
you have to accept that any difference
between the mean scores (as represented
on your bar chart) are just a fluke! You have
to accept the NULL hypothesis in this case

The research was then evaluated using
GRAVE