A researcher was interested in examining the effects of the amount of caffeine intake during the day on the quality of participants’ sleep quality of 50 male, sophomores at USF who were randomly selected. Quality of sleep was measured using an actigraphy and amount of caffeine was measured using a self-reported food diary. Is the sample used in the study a probability sample or a non-probability sample?
Read DetailsIf the researcher evaluated the measurement quality of the actigraphy by correlating the scores from the actigraphy (score range = 0 to 100 with higher scores representing higher quality) to the scores from the polysomnography (score range = 1.5 to 8.5 with higher scores representing higher quality), the gold standard used to measure sleep quality, what type of measurement evidence is this?
Read DetailsA researcher was interested in examining the effects of the amount of caffeine intake during the day on the quality of participants’ sleep quality of 50 male, sophomores at USF who were randomly selected. Quality of sleep was measured using an actigraphy and amount of caffeine was measured using a self-reported food diary. What effect would using 50 male, sophomores at USF have on internal validity?
Read DetailsA researcher examined the body mass index (BMI) of 1000 randomly selected undergraduates from USF and found a mean of 18 and a standard deviation of negative 0. 05 (SD=-0.05). What is your interpretation of the standard deviation of -0.05?
Read Details7 undergraduate students were randomly selected and asked to complete a questionnaire that asked how many total marathons (26.2 miles or 42.16 kilometers) they had completed. The results were: 7, 0, 0, 0, 2, 1, 4 What is the variance for the number of marathons?
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