Whether the given study depicts an observational study or a designed experiment and to identify the response variable. The study is conducted to compa

Study design
asked 2021-02-12
Whether the given study depicts an observational study or a designed experiment and to identify the response variable.
The study is conducted to compare the battery lives of a brand-name battery and a generic plain-label battery in digital cameras. For this purpose, 30 digital cameras are randomly selected and divided into 2 groups, one of the groups uses the brand-name battery while the other one uses the generic plain-label battery. In both the cameras, pictures are taken under identical conditions by keeping all variables, except the battery-type, in control.

Answers (1)

Observational Study: An observational study measures the values of a variable without influencing the values of response variables and explanatory variables. Thus, in an observational study, researchers can observe the behaviors of the individuals without influencing the outcome of that study.
Designed experiment: In a designed experimental study, the researchers allocate individuals to a certain group under study and change the values of an explanatory variable intentionally, after which, the values of the response variable for each group is recorded.
The 2 battery-types are the 2 treatments provided to the cameras (individuals), which are influenced intentionally, under a controlled setting and the battery-lives noted for each individual. Hence, the study is a designed experiment.
Response variable: The focus of a question in a study of the experiment is response variable, where one is interested to make measurements and form conclusions about it.
The focus of the experiment is a comparison between the ‘battery-lives’ of two types of batteries, which are measured in the experiment. Hence, the battery life is the response variable.
Best answer

expert advice

Need a better answer?

Relevant Questions

asked 2021-06-01
Determine whether the study depicts an observational study or a designed experiment. Identify the response variable in each case. A sport s report er asks 100 baseball fans if Barry Bonds's 756th homerun ball should be marked with an asterisk when sent to the Baseball Hall of Fame.
asked 2021-06-24
State whether the investigation in question is an observational study or a designed experiment. Justify your answer in each case. The National Association of Colleges and Employers (NACE) compiles information on salary offers to new college graduates and publishes the results in Salary Survey.
asked 2020-11-26
Use either the critical-value approach or the P-value approach to perform the required hypothesis test. For several years, evidence had been mounting that folic acid reduces major birth defects. A. Czeizel and I. Dudas of the National Institute of Hygiene in Budapest directed a study that provided the strongest evidence to date. Their results were published in the paper “Prevention of the First Occurrence of Neural-Tube Defects by Periconceptional Vitamin Supplementation” (New England Journal of Medicine, Vol. 327(26), p. 1832). For the study, the doctors enrolled women prior to conception and divided them randomly into two groups. One group, consisting of 2701 women, took daily multivitamins containing 0.8 mg of folic acid, the other group, consisting of 2052 women, received only trace elements. Major birth defects occurred in 35 cases when the women took folic acid and in 47 cases when the women did not. a. At the 1% significance level, do the data provide sufficient evidence to conclude that women who take folic acid are at lesser risk of having children with major birth defects? b. Is this study a designed experiment or an observational study? Explain your answer. c. In view of your answers to parts (a) and (b), could you reasonably conclude that taking folic acid causes a reduction in major birth defects? Explain your answer.
asked 2021-06-19
When two targets are presented close together in a rapid visual stream, the second target is often missed. Psychologists call this phenomenon the attentional blink (AB). A study published in Advances in Cognitive Psychology (July 2013) investigated whether simultaneous or preceding sounds could reduce AB. Twenty subjects were presented a rapid visual stream of symbols and letters on a computer screen and asked to identify the first and second letters (the targets). After several trials, the subject's AB magnitude was measured as the difference between the percentages of first target and second target letters correctly identified. Each subject performed the task under each of three conditions. In the Simultaneous condition, a sound (tone) was presented simultaneously with the second target; in the Alert condition, a sound was presented prior to the coming of the second target; and in the No-Tone condition, no sound was presented with the second target. Scatterplots of AB magnitude for each possible pair of conditions are shown below as well as the least squares line for each. a. Which pair of conditions produces the least squares line with the steepest estimated slope? b. Which pair of conditions produces the least squares line with the largest SSE? c. Which pair of conditions produces the least squares line with the smallest estímate of σ?