Practical Investigation (Edexcel A-Level Psychology): Revision Notes
Guide to the Practical Investigation
Learning outcomes
Students undertaking the practical investigation in Child Psychology must demonstrate competence in several key areas. The investigation requires you to design and carry out a study using one of three research methods: an interview, a questionnaire, or an observation. Your research must include a clearly stated hypothesis, a well-justified research method, an appropriate sample selection, and a comprehensive discussion of findings.
The practical investigation assesses your ability to apply psychological research methods in a real-world context. You'll need to demonstrate competence across multiple areas: research design, ethical application, data analysis, and critical evaluation.
The practical investigation also demands the application of ethical principles throughout the research design. You must analyze and present quantitative data collected during the study, and use appropriate statistical tests such as chi-squared, Mann-Whitney U, Wilcoxon, or Spearman's rho to analyze research findings. Finally, you need to evaluate your practical work by considering both the strengths and weaknesses of your approach and suggesting possible improvements.
Research question and hypothesis
Developing a research question
Your research question forms the foundation of your investigation. It should address a relevant issue in child psychology that can be explored through your chosen research method. The question must be specific enough to allow for focused data collection yet broad enough to yield meaningful findings.
For the practical investigation, an example research question explores whether day care can provide beneficial experiences for young children. This topic is relevant because psychological research has examined both positive and negative effects of day care on children's social, emotional, and cognitive development. The investigation focuses specifically on parental views regarding the positive experiences of young children in day care settings.
Formulating hypotheses
Once you have established your research question, you must formulate appropriate hypotheses. The hypothesis should be testable and related to your chosen research method. For investigations comparing two groups or conditions, you need to state both a null hypothesis and an alternative hypothesis.
Worked Example: Day Care Investigation Hypotheses
The investigation examines whether parents of children under three years old believe their children experience more positive outcomes in a nursery compared to a preschool environment.
Several factors may influence parental responses:
- Operational differences: Preschools typically operate during mainstream education hours, meaning children attending nursery may spend longer periods in day care
- Age requirements: Preschools often require children to reach certain developmental milestones (such as being potty trained), whereas nurseries accept children from a very young age
- Educational emphasis: Although preschools may emphasize academic development, nurseries must also provide learning opportunities aligned with preschool provision
- Staff qualifications: Preschool staff tend to be more highly qualified than nursery staff
Due to these differences, predicting the direction of parental responses proves difficult. Therefore, a non-directional (two-tailed) hypothesis is appropriate.
Alternative hypothesis: Parents will report differences in the degree to which they perceive positive experiences for their children in nursery compared to preschool.
Null hypothesis: No difference will exist in parental reported positive experiences of day care between nursery and preschool settings.
A non-directional (two-tailed) hypothesis is appropriate when you cannot confidently predict which direction the results will go. This type of hypothesis acknowledges that a difference will exist but does not predict which group will show more positive experiences.
Research method: Structured interviews
Understanding structured interviews
The practical investigation employs a structured interview as the research method. A structured interview involves using prepared questions that are asked in a standardized order to all participants. This standardization ensures that the same questions are posed to each interviewee identically, allowing for more reliable comparisons between responses.
The type of questions you use influences the nature of data obtained. Closed questions provide participants with a fixed set of response options and yield quantitative data that is easier to measure and test for reliability. Qualitative data obtained from open questions allows parents to expand on their responses, providing richer information. However, open questions will not be as structured as closed questions.
Interview construction
When constructing your interview schedule, you should prepare a series of questions designed to be asked exactly as worded. This standardization means the same questions are asked to each interviewee in the same order. However, open questions allow flexibility in parental responses and will not be as structured as closed questions.
The wording of questions must reflect the background of interviewees, including their age, educational background, social class, and ethnicity. Consider your target audience carefully when designing questions to ensure they are appropriate and understandable.
You also need to consider how data will be recorded. Writing notes as the interview progresses can be useful, although you may not transcribe everything being said. Many researchers record interviews and create written transcripts later, which are written descriptions of interview questions and answers that can be analyzed subsequently.
For the day care investigation, sample interview questions include:
- On a scale of 1 to 5, how would you rate the experiences of your child in day care (1 being not positive and 5 being very positive)?
- Is your child most often happy when they come home from day care?
- Do you believe that your child has benefited intellectually/academically from being in day care?
- Do you feel that your child has benefited socially from day care?
- Is your child more able to play with other children as a result of being in day care?
- Do you feel that your child has become more independent from their experience in day care?
Scoring responses
The first question uses a scaled response, so a low score indicates less positive experiences whilst a high score indicates more positive experiences.
Questions 2–6 elicit short or lengthy responses from parents. These can be quantified as either a yes/no response based on the overall answer to each question, receiving a score of zero for a no response and a score of 1 for a yes response. Scores can then be totalled to give an overall measure of positive experiences. Alternatively, you may rate each response on a scale if parents provide more detail.
Worked Example: Scoring Interview Responses
Parent 1: question 1 = 3, question 2 = 1, question 3 = 0, question 4 = 1, question 5 = 1, question 6 = 1
Total score: 7
Parent 2: question 1 = 5, question 2 = 1, question 3 = 1, question 4 = 0, question 5 = 0, question 6 = 0
Total score: 7
These responses are equal in total, suggesting both parents believe their children experience reasonably positive outcomes from day care. However, you may break this down further and analyze the type of responses given. For example, parent 1 believes their child benefits more academically from day care but not socially, whereas parent 2 believes their child has benefited socially but not academically from day care.
Interviewer effects
Interviewer effects can introduce bias into study results and compromise validity. As interviews are social interactions, the appearance of the interviewer may influence how the interviewee responds. This includes the interviewer's age, gender, ethnicity, body language, and social status.
When interviewing parents, be mindful that parents often feel guilty about placing their child in day care. You should be sensitive to this and brief them fully on the aims of your study. Approaching people you are familiar with can be useful, as asking strangers about their children's experiences of day care may result in an uncomfortable situation.
Sampling
Importance of sampling
Selecting your sample is an important consideration as it determines how representative of the population your findings are. Several sampling techniques are available to researchers, although not all are suitable for every investigation.
Volunteer sampling
Volunteer sampling involves asking parents to take part in response to an advert. This method is quick and relatively easy to implement and can potentially reach a wide variety of participants, depending on where you advertise.
Volunteer Sampling - Strengths and Limitations:
Strengths:
- Quick and relatively easy to implement
- Can potentially reach a wide variety of participants
- Participants are genuinely interested and willing to offer opinions
Limitations:
- Volunteers may not be representative of the target population
- Participants may be more motivated to take part
- They may have particular views they wish to express
Snowball sampling
Sometimes samples of people are difficult to access unless you have friends and family connections. In such cases, a snowball sampling technique may be more useful. Gaining access to a single participant in the target population can permit access to other participants they may know. You also need to consider what might be a realistic target number for your sample, given that interviews are time-consuming.
Opportunity sample for the day care investigation
For this practical investigation, an opportunity sample of family and friends who are parents of three-year-old children will be used. The sample comprises five parents with a child in preschool and five parents with a child in a nursery. Either the mother or father (or guardian) will take part in the interview, depending on their availability.
Ethical considerations
Essential ethical guidelines
Essential Ethical Guidelines for Child Research
Adhering to ethical guidance is of the utmost importance when using children in research. You need to ensure your study adheres to relevant ethical guidelines, including:
- Briefing and debriefing participants
- Gaining informed consent
- Allowing for the participant to withdraw at any time from the study
- Competence in research conduct
- Avoiding deceiving your participants
- Privacy and confidentiality
Helpful mnemonic: BICAP
- Briefing and debriefing
- Informed consent
- Confidentiality
- Avoid deception
- Privacy
Specific considerations for day care research
The interview focusing on positive aspects and experiences of children in day care is potentially less problematic than asking questions about negative experiences, as the overall assumption is reassuring for parents rather than highlighting negative effects on children. However, it remains essential that interviews are approached with sensitivity, as many parents feel guilt about leaving their child in non-maternal care.
All information gathered must be treated with confidentiality. Any identification of a particular child or indeed the day care provider could be problematic. Asking intrusive questions should be avoided, as most parents will be sensitive to the needs of their child. You should also ask your teacher to check your interview schedule or questionnaire, as they are a more competent judge of ethical issues.
Example Brief for Participants
"Thank you for agreeing to take part in an interview to investigate the experiences that you believe your child to have in their day care centre. This interview is designed to record the different positive experiences of children who attend a nursery compared to a preschool. You should try to be as honest as possible in your answers. You will be asked a series of questions and be given time to express your own opinions. The interview should last around 10 minutes and all of your answers will remain confidential and your child, you and the day care provider will be anonymised. You can choose to not answer any of the questions that are asked or decide to not take part in the interview at any point.
My research supervisor is my teacher at school, who can be contacted by phone or email on: [contact details]
Again, thank you for taking part in my investigation. The findings will be written up and available at your request. Following my A-level examination, the results gathered for this investigation will be destroyed."
Data collection tools
Recording interview data
It is important that data gathered from your interview is recorded accurately. This could be via handwritten notes or by tape recording each interview and writing up as a transcript later.
Closed interview questions, such as 'How many friends has your child made at nursery?' will yield quantitative data such as the number of friends. This can be easily counted. If you choose to use open-ended questions, such as 'What are the social benefits of sending your child to nursery?' this will yield more qualitative data and a variety of different and personal responses regarding parents' perceptions of social benefits.
Thematic Analysis for Qualitative Data
Thematic analysis typically involves the analysis of repeated themes in the data. For instance, parents might commonly mention 'a number of friends at nursery', 'my child is more sociable', or 'my child engages more with adults'. These could then be 'counted up' as instances of the social benefits of attending day care.
Data analysis
Deciding on analytical approach
You need to decide how to analyze your data in relation to your initial hypothesis. This requires deciding how to measure positive experiences. For example, this could be analyzed quantitatively by counting the number of positive experiences reported by parents or devising a scoring system for yes/no responses.
Mann-Whitney U test
As the investigation is interested in the difference between nursery and preschool provision and positive experiences, a Mann-Whitney U test would be an appropriate test for significance in this particular instance. Results can be presented in a table and a graph to visually represent the data gathered.
The table below shows the total score for positive experiences (socially and academically) rated by parents of children in nursery and preschool day care:
| Preschool care (Total rating/10) | Nursery care (Total rating/10) | A. Rank for preschool care | B. Rank for nursery care |
|---|---|---|---|
| 9 | 6 | 9 | 4 |
| 7 | 7 | 6.5 | 6.5 |
| 5 | 8 | 1.5 | 8 |
| 6 | 6 | 4 | 4 |
| 5 | 10 | 1.5 | 10 |
| Sum total of ranks | 22.5 | 32.5 |
Applying the Mann-Whitney U formula
Worked Example: Calculating Mann-Whitney U
The formula for the Mann-Whitney U can be applied to the sum total of ranks as follows.
Note that is the sum total of ranks for list A and is the sum total of ranks for list B.
The lowest value of or is the U value taken. In this case, the U value is 7.5.
This should be compared to the table of critical values for a two-tailed test at 0.05.
Extract of a Mann-Whitney U table of critical values for a two-tailed test at 0.05:
| = 5 | 6 | 7 | |
|---|---|---|---|
| 5 | 2 | 3 | 5 |
| 6 | – | 5 | 6 |
| 7 | – | – | 8 |
The calculated value must be equal to or less than the critical value in this table for significance to be shown.
Interpreting results
The U value = 7.5, which is more than the critical value of 2 for a one-tailed test (which we will assume in this instance). Therefore, the results are not significant at the 0.05 level of significance (>0.05) and the null hypothesis should be accepted. This means there is no difference in the positive experiences of children who attend nursery or preschool day care.
Understanding Significance Levels
If >0.05 it means that the probability of the results being due to chance is greater than 5 per cent, therefore the null hypothesis should be accepted as the results are not significant.
If <0.05 it means that the probability of the results being due to chance is less than 5 per cent, therefore the alternative hypothesis can be retained.
Check the direction of the symbols that indicate probability is greater than (>) or less than (<) very carefully.
Examination Tip: Using Critical Value Tables
In your examination, there will be tables of critical values to choose from. It is important, especially for the Mann-Whitney U test, that you select the correct table to use. Carefully read the instructions at the top of the table to help with your selection. You will probably be required to use a table at the significance level of 0.05, unless otherwise instructed. You will need to select the correct table for a one-tailed or two-tailed test based on whether your hypothesis is directional or non-directional.
Discussion
The final section of your practical investigation is the discussion. The overall aim of this section is to interpret your findings in relation to previous research and to critically reflect on your study. This part of your practical investigation should include the following sections.
Offer an explanation of your findings
Explain what was found in relation to your hypothesis. In this particular instance, you could say that the alternative hypothesis was not supported as the difference between the positive experiences of nursery and preschool children was not significant and could be due to chance factors. It is also useful to provide a summary of your descriptive statistics. In this case, no real differences between nursery and preschool children emerged from the data.
Explain how your findings relate to previous research
Reflect on whether your research supports, disputes, or extends the knowledge of previous research and theory. Think about whether the theory or other studies could be reconsidered as a result of your findings.
Studies such as Vandell et al. (1988) found a positive correlation between children's positive interactions with adults and ratings of peer acceptance, social competence, and empathy four years later. There seemed to be no difference between children attending preschool or nursery, which is perhaps predicted from the congruence in governmental policy between the different providers.
Limitations of your practical investigation
You should be critical of your research and suggest possible limitations of your current study. For instance, was your sample representative? Were there any potential biases or confounding variables that could have affected the data? If relying on parents' self-ratings of quality, there may be an element of bias involved. You should suggest how such issues could be resolved and suggest improvements for any further research.
Example Limitations in Day Care Study
In this practical example, it is likely that parents reported their children having more positive experiences because they would not wish to appear to place their children in day care where they would have negative experiences. It is also likely that parents would be more favourable about day care choices they have made for their own children. The motivation behind self-reported responses must be explored fully to establish whether the findings are valid or not.
The sample used can also be criticised for being based on a small number of parents recruited by opportunity sample. This sample is not only unlikely to represent the views of all parents but is likely to be biased towards those parents who are willing to discuss day care experiences of their children. These are more likely to be positive experiences, as parents may not wish to participate in such an interview had their children had negative experiences of day care.
You should also consider the way in which your questions were constructed, in order to assess the validity of your findings. Questions can often be leading or generate socially desirable answers.
Strengths of your practical investigation
You should also consider the strengths of your practical investigation. Here it is useful to consider the ethical guidelines you adhered to and the methodological considerations that made your study reliable or valid. You may also wish to consider the implications of your findings, as this can also be a strength of the research.
Example Strengths in Day Care Study
In this practical investigation, parents were fully informed about the nature of the research aims, the procedure, and were also given the right to withdraw and have access to the report findings. Data protection was taken into account as the findings were destroyed after use. None of the questions asked in the interview violated a right to privacy and the results were anonymised to ensure confidentiality was not breached.
Although an interview was the research method used, it was a structured interview and a strict schedule was followed to ensure that all participants were asked the same questions in the same format. This standardised procedure was used to ensure the study could be repeated and improves the reliability of the research.
Identifying the strengths of your practical investigation can sometimes be difficult. It can be useful to compare your research method and procedure with alternative choices, such as a questionnaire or observation, and discuss why your design choices were better.
Suggestions for improvement
Review the weaknesses of your practical investigation to highlight possible areas for improvement. It could be argued that a larger and more diverse sample of parents with children aged three years would have produced more reliable and generalisable findings. As it is important to develop your suggestions for improvement, you need to explain exactly what you would have done to implement your ideas.
For this practical, it would have been better to have accessed a range of nurseries and preschools, perhaps conducting background research on the quality of day care provided by reading their Ofsted reports. A random sample of three-year-old children could be gathered by assigning each child a number and using a random number generator to select a random sample. The parents of these children could have then been contacted for their agreement to participate.
Exam Tip: Developing Suggestions for Improvement
Suggestions for improving your practical investigation need to be well developed. Follow this format to explain your suggestions better:
- State your suggested improvement - What specific change would you make?
- Explain why the improvement is needed - What problem does it address?
- Describe how you intend to implement your improvement - 'How' is a process, so detail each stage
- Explain the implications of your suggestion - How will it improve the practical?
Key Points to Remember (RELS Framework):
- Results explained - Interpret your findings in relation to your hypothesis and provide descriptive statistics
- Earlier research - Relate your findings to previous research and theory, discussing whether you support, dispute, or extend existing knowledge
- Limitations - Critically evaluate weaknesses including sample representativeness, potential biases, and confounding variables
- Strengths - Discuss ethical adherence, methodological rigor, reliability, validity, and positive implications of your research
- Plus: Always include well-developed suggestions for improvement following the four-step format