Investigation 1

• Variables

  IV- The self-reported age of the ppts in years. Its operationalised by age in two categories (16-19 and 25+).

  DV- A self-report of the ppts sleep quality over the previous month during the Pittsburgh Sleep Quality Index. Its operationalised as a self-report of the ppts sleep quality over the previous month using PSQI.
• Hypotheses

  Non-directional- there will be a statistically significant difference in self-reported quality of sleep between teenagers and adults.

  Null- there will no significant difference in self-reported quality between teenagers and adults.

  Directional hypothesis- would be chosen if previous research was more consistent in this area.
• Research Location

  We used a field location since it was not a controlled environment which is the sixth-form college site.

  Advantage- not artificial which improves ecological validity.

  Disadvantage- less control over extraneous variables since locations may be loud.
• Methodology

  This is a quasi-experiment as the IV is naturally occurring.

  Advantage- allows us to see differences without direct experimental manipulation.

  Disadvantage- cant state a clear cause and effect relationship between age and sleep quality.
• Methodology

  Uses an independent group design as different ppts are used in different conditions.

  Advantage- order effects wont occur as each ppts is only taking part in one condition based on age.

  Disadvantage- lack of control over ppts variables
• Sampling Method

  We used opportunity sampling and 19 teenage ppts, 19 adult ppts.

  Advantage- less time-consuming so allows more time to be spent on perfecting the design.

  Disadvantage- may be unrepresentative so results cannot be generalised to the wider population.
• Ethical Issues

  Lack of valid consent- ppts weren't made fully aware of the purpose.

  Dealing- we gained presumptive consent from a different group of teenagers of the same age.

  Psychological harm- ppts may find answering some questions uncomfortable.

  Dealing- in the briefing ppts were told all responses would be kept confidential and no data is recorded.
• Descriptive Statistics

  Mean- Takes into account all scores on the PSQI from every ppts. Teenage = 9.7 and adult = 9.8

  SD- shows the spread of data and if there are large variations in scores. Teenage = 2.9 and adult = 3.6
• Graphical Representations

  A bar chart is appropriate because our data is in separate conditions. It provides a visual representation to show the difference in global PSQI score.

  Our graph shows us that the adult condition had a higher score of 9.8 than the teenage condition with 9.7
• Inferential Statistics

  Level of measurement used is ordinal. We tested differences as only one numerical variable is used. An independent group is used and a Mann Whitney U test is used.
• Findings and Conclusions

  Findings- Teenage condition scored less on the global sleep quality test with a mean score of 9.7 compared to adults with 9.8.

  Conclusions- teenagers get better sleep with results from the PSQI
• Issues of Validity

  Internal- a self-report questionnaire has a risk of social desirability bias. Dealing- an alternative method of measuring sleep can be used like a sleep lab.

  External- sample is unrepresentative. Dealing- stratified sampling could be used to gather a representative sample.
• Checking Validity

  We used face validity by asking our ppts what they thought they ere being tested on. This method was time-efficient compared to contents validity which would involve an expert reviewing the PSQI.
• Issues of Reliability

  Internal- we had multiple student researchers using different locations

  Dealing- a standardised location would be used

  External- locations were not recorded which could prevent replication

  Dealing- initial locations should be recorded to ensure detail
• Checking Reliability

  We used test-retest where students were asked to repeat the study 1 month after and results were compared. This was chosen as we wanted to establish if sleep quality was consistent over time.
• Improving Research

  We could use a larger more diverse sample which allows for more detail to be obtained. We could also ask for a sleep diary where data is compared which improves internal validity.