4 - psychology PDF

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Summary

psychology...

Description

Research Designs ●

Repeated Measures

Description

Advantages

The same group of participants are exposed to both the experimental and control group

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Disadvantages

Individual differences highly controlled Fewer participants are required

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Matched participants Description Placing equivalent pairs of participants into the control and experimental group.

Advantages ● ●

Mininises participant differences Eliminate order effects

Disadvantages Pre-testing ius time consuming and therefore expensive If one person drops out- so does the data for the pair

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Independent group Description

Advantages

The participants are only exposed to the experimental or control conditions.

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Order effects can occur Participants have to take part in both conditions so ‘dropouts’ are more likely.

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Time efficient and easy to use Less chance of drop outs

Disadvantages ● ●

Participant differences not controlled for. More participants needed than repeated measures

Overall Explained with examples

Repeated measures

Matched participants

Independent group

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Cross- sectional studies ●

Participants of different ages are investigates at one particular point in time ● +Data is collected only once, so it is less expensive and more time efficient ● +Short term commitment, less drop outs ● -Cant establish cause and effect ● -Factors other than age may play a part in results(eg. Family environment, schooling, friendship groups, etc)

Extraneous and confounding variables Extraneous variables

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Extraneous variable:variable other than the Iv that causes a change in the Dv. Makes it difficult to determine whether the change in the DV was solely to the IV Confounding Variable Confounding variable:Variable other than the Iv that has an unwanted systemic effect on the Dv. Can not conclude that the IV alone caused a change in the Dv ● Example ● Study is conducted to investigate whether boys or girls are better at math

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Iv:Gender Dv:Math ability Sample ● -Girls aged 16-17 ● Boys aged 14-15

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Age is a Cv-any difference in result between groups maybe due to age not gender Examples of EV and CV Individual differences Order effects Placebo effects Experimenter effects Non standardised instructions and procedures

Individual participants differences

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Includes memory ability, motivation,mood,gender,ethnicity,personality,piro experiences,IQ etc.. Ways to minimise Matched participants or repeated measures design..

Order effects When both the control and experimental groups are made up of the same people. It can result in improved or improved performance(due to practise, boredom, fatigue). ● Ways to minimise ● Counterbalancing ● Increasing the time period between the two conditions.

Placebo effects Placebo:A fake treatment(pill or injection) Placebo effect:change in behaviour caused by the belief that one is receiving some kind of experimental treatment. ● Ways to minimise: ● Single blind procedure

Experimenter effects Experimenter effect:refers to change sin participants behaviour that are caused by the unintentional influence of an experiment, rather than the effects of the IV ● Ways to minimize ● Double blind procedure.

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Non-standardised instructions and procedures

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Only difference between group- E and group-C should be the Iv Standardised instructions and procedures are essential Eg. -language used -Different researches -testing conditions -time of the day.

● Types of data ●

Subjective data

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Data collected through observations of behaviour or based participants self reports Based on opinion,so its biased

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Objective data

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Measured according to identifiable criteria Data usually in numerical form.

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Qualitative data

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Descriptions of characteristics of what is being studied, often expressed in words. E.G observations,interviews +more detail provided -Difficult to statistically analyse, open to bias

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Quantitative data

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Measurements-numerical information about the variable being studied +quick and easy to statistically analyse -lack of detail

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● Types of research methodology

● Validity and reliability ● ●

Validity-Refers to the extent to which a study measures what its supposed to measure(jump on /off scale same result0 Reliable-refers to the extent to which results obtained from a study are consistent.

● Descriptive and inferential statistics ●

Descriptive statistics:

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Used to analyse, organise, summarise and describe the results

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Eg:

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Tables Graphs Measures of central tendency variability(range and standard deviation)

● Inferential statistics

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Mathematical calculations that allow us to interpret the data and determine whether the results are meaningful or not. What is an acceptable difference between the mean scores? Allows us to determine whether results support the hypothesis and f we can draw conclusions Allows us to determine whether the difference between the two groups is significant enough to say that the Iv has affected the Dv and not chance, Iv has an effect on Dv.

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Conclusion

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A conclusion is an inference as to whether the hypothesis has been supported or rejected Never ‘proven or disproven’ Consider -Cv’s (variables that had effect on results) _Inferentials statistics (difference between groups effect)

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Generalisation

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A generalisation is a statement that relates the findings of the investigation to the wider population Consider -obvious flaws of the experiment( CV’s) -Sampling procedure used Is the sample size large enough Inferential statistics.

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● Ethics ● ● 1. 2. 3. 4. 5. 6.

Ethics::moral principles and standards that guide people in identifying good,desirable or acceptable conduct. Role of ethic committee Confidentiality Voluntary participation Informed consent Withdrawal rights Deception debriefing ○ Ethics Acrostic- ery ntelligent udes an o ell. ○ (Voluntary participation, Informed consent, Deception, Confidentiality, Debriefing, W ithdrawal rights)

○ Applying Key science skills ○

Science skills scenario 1:

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In a study designed to test whether loud music interferes with problem-solving skills, 50 randomly selected participants were randomly assigned into 2 separate groups. One group was asked to complete 5 problem solving tasks while listening to loud music The second was asked to complete five problem solving tasks under quiet conditions. The quiet conditions group were found to be more successful in completing the problems living task. Based on the mean difference between each group, the researchers concluded that cognitive ability is adversely affected when loud music is being played.

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1. Why is this study considered to be an experiment?

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2. Identify the operationalised IV and Dv?

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3. Which group of students formed the control group in this study? The group that compelled the five problem solving tasks under quiet conditions (also known as group 2.) 4. Why is it important to have a control group in an experiment? As a basis of comparison between the experimental and the control group. This will allow the experimenter to see if the Iv has an affect on the Dv. 5.What type of data was collected in this study? Outline one advantage of this type of data. It is quantitative data, and an advantage of using quantitative data is that it is numerical and therefore easier to compare data.

○ Science skills scenario 2:

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Dr Brodsky investigates if first year university students driving speed is related to the speed of the music that they listen to while driving. The speed of the music is measured by the number of beats per minute(bpm). He decided to conduct his research using first year university students at samson university. He used a lottery system to obtain a random sample of 28 students. All students drove in a driving simulator under all four conditions.

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Condition 1 students driving without listening to music Condition 2 students driving to music at 40-70 bpm Condition 3 students driving to music at 85110 bpm Condition 4 students driving to music at 120-140bpm

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What is the aim of this study?To investigate if driving speed is related to the speed of music listened to while driving. What is the operationalised Iv and Dv for this study? Whether students drove without listening to music or drove while listening to music at speeds of 40-70bpm,85-110 bpm, or 120-140bpm. As Well as the Average Kilometers(or speed in kms) that students drove over the speed limit. 3. Write a research hypothesis for this study. It was hypothesized that first year uni students who listen to fast music while driving would be more likely to drive over the speed limit than students who listened to slow music , or none while driving. 4. Dr Brodsky used random sampling to generate his sample. Name an alternative sampling technique that he could have used to generate a more representative sample and describe how he would generate this sample. Stratified sampling. Dr Brodsky would need to divide the population to be studied into strata based on characteristics relevant to the study, such as gender, driving ability, years spent driving etc. Dr Brodsky would then need to select a sample from each start in the same population as the sub-groups that occur in the population. 5. Evaluate the experimental design that was used in his experiment and suggest how any limitations might be overcome. Repeated measures research design.(Orders effects can occur.)The subjects may become bored/fatigued after completing 1st conditions and therefore will perform sore in subsequent conditions. Or practise effects may occur where subjects perform better in the subsequent conditions due to former experience. Dr Brodsky could counterbalance groups by arranging the order in which the conditions are experienced so that each condition occurs equally as often in each position. 6. Can a conclusion be made for this study? Justify your response. No conclusions can be made. Conclusions cannot be made from descriptive statistics.

Chapter 5...