Research methods Lesson 2

In your pairs, create 6 questions on the following topics: Research method quiz In your pairs, create 6 questions on the following topics: Hypothesis (IV and DV) Research methods

Task: Correlations What is called when both variables increase? (1) What is it called when one variable increases and the other variable decreases? (1) What is the statistic called which shows the strength and direction of the correlation? (1) Using the following words, estimate the strength and direction of these scores (weak, moderate, strong, perfect, positive, negative, no) (7) 0.25 b) -0.80 c) 0.5 d) 0.12 e) 0 f) -1 g) -0.95 5) Give two advantages of using correlational research in Psychology (2) 6) Give two disadvantages of using correlational research in Psychology (2)

Task – Case studies 7) Define what is meant by a case study (1) 8) Identify one example of a case study used in the topic of memory (1) 9) Give two advantages of a case study (2) 10) Give two disadvantages of a case study (2)

Answers - Correlations What is called when both variables increase? Positive correlation 2) What is it called when one variable increases and the other variable decreases? Negative correlation 3) What is the statistic called which shows the strength and direction of the correlation? Correlation Coefficient

Answers - Correlations 4) Using the following words, estimate the strength and direction of these scores (weak, moderate, strong, perfect, positive, negative, no) 0.25 weak positive correlation -0.80 strong negative correlation 0.5 moderate positive correlation 0.12 weak positive correlation 0 no correlation -1 perfect negative correlation -0.95 strong negative correlation

Answers - Correlations Give two advantages of using correlational research in Psychology (2 marks) Can be used when research would be impossible or unethical to manipulate an IV. One can predict the value from one variable based on the value from another variable if they are correlated. Give two disadvantages of using correlational research in Psychology (2 marks) Cannot and must not infer cause and effect relationships Can only detect linear (straight line) relationships.

Answers – Case studies 7) Define what is meant by a case study A non-experimental research study in which one person (or small group) are studied in detail. 8) Identify one example of a case study used in the topic of memory Clive Wearing; The case of HM; 9) Give two advantages of a case study Rich in detail – provide great depth of unique cases Useful for theory contradiction 10) Give two disadvantages of a case study Not representative Risk of researcher bias

Sampling task Your task is to experiment with the different methods of sampling, using skittles as your participants. You will create each of the five sample types, recording the number of each colour skittle you obtain in your sample and the percentage. Thereafter, you will evaluate your samples, based upon how representative your sample is in relation to the target population.

Target population Tip all the sweets out of the bag and record how many of each colour there are, in the table below: Colour Number % Purple Orange Green Red Yellow Total

Random sampling Does it represent your target population? Define random sampling? Colour Number % Purple Orange Green Red Yellow Total Does it represent your target population? What are the strengths and weaknesses of the sampling technique?

Opportunity sampling Does it represent your target population? Define opportunity sampling? Colour Number % Purple Orange Green Red Yellow Total Does it represent your target population? What are the strengths and weaknesses of the sampling technique?

Volunteer sampling Define volunteer sampling? Imagine that you have placed a poster up in school, asking for participants to self- select and take part in your research. You’ll have to imagine that ‘green’ skittles are the most helpful and willing to take part, followed by ‘yellow’. The ‘orange’, ‘red’ and ‘purple’ skittles, definitely won’t want to take part! You are still looking to recruit 25 participants, but if you can’t manage to get 25, you’ll just have to run your experiment, with as many as you can. Record your results in the table below:

Volunteer sampling Does it represent your target population? Colour Number % Purple Orange Green Red Yellow Total Does it represent your target population? What are the strengths and weaknesses of the sampling technique?

Systematic sampling Does it represent your target population? Define systematic sampling? Colour Number % Purple Orange Green Red Yellow Total Does it represent your target population? What are the strengths and weaknesses of the sampling technique?

Stratified sampling You need to create a sample of 25 sweets that is similar to the target population, in terms of the percentage of each colour. If 15% of the sweets in your target population are green, you need to ensure that your sample (of 25) only has 15% of green sweets. For example: 15% of 25 = (15÷100) x 25 = 3.75. Therefore, you would need 4 sweets to represent your target population. Colour %

number if sweets needed for sample Stratified sampling Colour % in target population number if sweets needed for sample Purple Orange Green Red Yellow Total Does it represent your target population? What are the strengths and weaknesses of the sampling technique?

Question… Which sampling technique was the most representative of your target population? Which sampling technique was the least representative of your target population? Which sampling technique was the longest to complete? Why might this be a problem? Which sampling technique do you think was the best and why?

Tasks… Task 1: Complete the sampling activity of your handout from last lesson Task 2: Decide whether the following statement is true or false…

Quiz – True or False? Q1 A sample is a part of the whole group of people being studied TRUE FALSE Q2 A random sample is one where anybody who is available at the time are asked at random to be in the study Q3 A volunteer sample will always be biased because volunteers are likely to be very interested in the topic being studied and/or have a specific personality type (the volunteering type) that make them atypical of people in general Q4 Opportunity samples are often used in psychological research because they are cost and time effective and because other sample types are difficult to obtain Q5 A strength of a random sample is that it is assumed that chance selection will cancel out biases and provide a sample representative of the target population Q6 “The target population” is the same as “people in general” Q7 Student samples are ideal for psychological research, especially when psychology students are used, as they take the study seriously and are convenient for researchers based in universities Stretch! For any that you believe to be false – correct the statements so that they are actually true!

Quiz – True or False? (Be honest ) A sample is a part of the whole group of people being studied TRUE FALSE Q2 A random sample is one where anybody who is available at the time are asked at random to be in the study Q3 A volunteer sample will always be biased because volunteers are likely to be very interested in the topic being studied and/or have a specific personality type (the volunteering type) that make them atypical of people in general Q4 Opportunity samples are often used in psychological research because they are cost and time effective and because other sample types are difficult to obtain Q5 A strength of a random sample is that it is assumed that chance selection will cancel out biases and provide a sample representative of the target population Q6 “The target population” is the same as “people in general” Q7 Student samples are ideal for psychological research, especially when psychology students are used, as they take the study seriously and are convenient for researchers based in universities Stretch! For any that you believe to be false – correct the statements so that they are actually true!

EXPERIMENTAL DESIGN Repeated measures design Participants take part in both conditions of the experiment (1 group) Advantages: Avoids the problem of participant variables. Fewer people are needed. Disadvantages: Order effects are more likely to occur. Demand characteristic more likely as participants might guess the aim as they take part in all the conditions. There are 3 different ways to carry out the experiment with participants. These are known as Experimental Designs. Independent measures design Counterbalancing: Alternating the order in which participants perform in different conditions of an experiment. For example, group 1 does ‘A’ then ‘B’, group 2 does ‘B’ then ‘A’ this is to eliminate order effects. Participants only take part in one condition of the experiment (2 separate groups) Matched pairs design Advantages: Avoids order effects. If a person is involved in several tests they man become bored or tired . Less demand characteristic as they do only one condition. Disadvantages: More people are needed than with the repeated measures design . Differences between participants in the groups may affect results, for example; variations in age, sex or social background. These differences are known as participant variables. Participants are matched in each condition for characteristics that may have an effect on their performance. e.g. A memory test Advantages: Reduces participant variables. Avoids order effects. Disadvantages: Very time-consuming trying to find closely matched pairs. Impossible to match people exactly. Requires more participants.

Descriptive statistics Measure of central tendancy: Mean: This is calculated by adding all the scores in a data set together and dividing by the number of scores. Mode: This is the most commonly occurring score. In some data sets, there may be more than one mode (bi-modal). Median: This is calculated by putting all the scores in a data set in order, and identifying the score in the middle. In an even numbered data set, the two middle scores are added together and divided by 2 to find the median.

Descriptive statistics Measure of dispersion Range = the difference between the highest and lowest numbers Standard Deviation = loosely defined as the average amount a number differs from the mean Variance = how spread out (far away) a number is from the mean

Descriptive statistics Measure of dispersion Standard deviation is a measure of dispersion that shows the spread of scores around the mean. A low standard deviation means that most of the numbers are very close to the average OR in other words… The lower the standard deviation, the less spread out the scores are around the mean. A high standard deviation means that the numbers are spread out OR in other words… The greater the standard deviation, the more spread out the scores are around the mean.

Descriptive statistics Complete the handout on descriptive statistics

Next lesson (Lesson 3) For those of you that would like to read ahead…. Pilot studies Ethical issues Peer review How we create….

Research methods Lesson 3