INVESTIGATION ONE: VARIABLES

Question 1

identify the IV in your experiment.

Answer 1

• quasi-IV - the existing chronological age condition between participants.
• calculated by asking DOB - age operationalised as chronological age rather than biological age.
• then categorised into 4 developmental groups, adolescents, young/middle-aged/older adults

Question 2

why is this a quasi-IV?

Answer 2

• The quasi-IV was an existing chronological age condition,
• not directly manipulated by the researcher, as it arises, or progresses, naturally.

Question 3

identify the DV in your experiment.

Answer 3

• DV - sleep quality,comprising
• sleep duration (“On average how many hours of sleep do you get per night?”)
• habitual bed + wake time,
• sleep satisfaction, using ordinal scales to rank their quality of sleep from 1-10, whether they feel rested upon waking or they could benefit from more sleep,
  inspired by the structure Pittsburgh Sleep Quality Index (PSQI) for greater concurrent validity.

Question 4

explain why the IV was operationalised in this way. 1/2, refer to TYPE of age

Answer 4

chronological age over biological age
* greater generalisability, due to its cost-effectiveness + ease in quantification.
* latter is mutable – affected by lifestyle and health factors.
* bio age requires invasive + expensive lab equipment to assess -> impractical for both the researcher + participants, AWA limiting construct + ecological validity.

AWA = as well as

Question 5

explain why the IV was operationalised in this way. 2/2, refer to age groups

Answer 5

• groups were defined by the researchers as they reflect distinct developmental changes that could affect sleep patterns,
• for instance increase in daily stressors with family responsibilities and employment in young or middle adulthood.
• Thus enabling valid comparisons to be made across lifespan.

Question 6

explain how the IV was operationalised in this way. 2/2, refer to age groups. give descriptions of these groups.

Answer 6

This was operationalised by identifying four distinct groups reflecting different developmental stages across a lifespan.
1. Adolescents aged between 14-18 yrs still within secondary education,
2. young adults aged between 19-35 yrs, beginning higher education or early in their careers,
3. middle-aged adults aged 36 - 59 yrs, uptaking familial + life responsibilities, with stable employment,
4. older adults, aged 60-81 yrs, likely within retirement.

Question 7

explain why the DV was operationalised in this way.

Answer 7

• to capture multiple aspects reflecting sleep’s overall restorative function, such as duration, satisfaction + continuity.
• allows for greater generalisability + concurrent validity w. existing lit. such as the Pittsburgh Sleep Quality Index (PSQI)
• sleep -> defined in literature as a typical nocturnal state involving neurological restoration, consistent with evolutionary perspectives of sleep as an adaptive, essential process (Nelson et al., 2021), supporting a nomothetic approach to sleep.