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Designing Studies

The concept of designing studies is inextricably linked to the effectiveness of a statistical analysis which is implemented to test a particular null hypothesis of interest. It is the design of a study which is responsible for setting the format of a statistical analysis in terms of what tests will be conducted, what characteristics will be measured and so on. It has even been stated among the literature that in many ways the design of a study is more important than the statistical analysis itself1.

If a study is poorly designed, then the significance of the statistical analysis which follows will be negligible. When designing a study it is critical to consider various factors such as the controls which are to be maintained, the duration of the study, the sample size to evaluate and the surveying methodology, to name a few things. For example, a study designed with too many controlled variables will not be useful because in the natural world, there are many variables which change due to chance alone and thus, cannot be controlled for.

Within the academic literature, it is agreed that the design of a study or experiment is the backbone to good research2. The methodology portion of a scientific study, although it may be one of the more technical sections of a paper, is by no means the least important. It is the methodology of a study which allows data to be collected and analyzed appropriately.

When designing a study, factors such as the statistical power and sample size determination, are just a few of the quantifiable characteristics which need to be considered. Research is costly, not only in terms of resources, but also with respect to time, and therefore, designing appropriate and organized studies is the key to success.



1. BMJ Publishing Group Ltd. (2014). Study design and choosing a statistical test. Retrieved from

2.Knight, K.L. (2010). Study/Experimental/Research Design: Much More Than Statistics. Journal of Athletic Training, 45(1), 98-100. doi: 10.4085/1062-6050-45.1.98

Categories within Designing Studies

Effect Size

Postings: 12

The effect size is a measure which quantifies the magnitude of the relationship between the variables being compared in a statistical analysis.

Standard Error

Postings: 64

Standard error is a measurement which describes the deviation between a sample mean and the population mean, by calculating the standard deviation of the sampling distribution.

Statistical Power

Postings: 8

Statistical power refers to the probability that a statistical analysis will allow for the null hypothesis to be rejected.

Sample Size Determination

Postings: 187

Sample size determination refers to the process of selecting the number of units to be counted or measured in a statistical analysis.

Statistical Terms

I need some help understanding statistical terms: 1. What are the different methods for describing data? 2. What is the difference between qualitative and quantitative data? 3. What is the difference between discrete and continuous data? 4. What is the difference between nominal, ordinal, interval, and ratio data?


Could you please provide some possible test questions based on the following chapters from these articles in the link. Read chapter 5 and 6 from the web link below. write 4 good questions from chapter 5 and 4 good questions from chapter 6

Planning an experiment

Question1 Mary is planning a study to see if learning of 6th graders on a math lesson is affected by background noise level. She wants to use a t-test for independent groups to analyze her results. Help her plan her study. What is her independent variable (IV) here? Describe two conditions she could create for the IV in her stu

Non-Experimental Research Methods: Qualitative Perspectives

Select one of the non-experimental methods (naturalistic observation, ethnography, case history, sociometry, archival study, and content analysis), and describe how you might use this method to study your hypothetical research question from a more qualitative perspective. Why did you select this particular method for your resear

Study designs and validity threats

1. Explain and give examples of how the particular outcomes of a study can suggest if a particular threat is likely to have been present. 2. Describe each of the following types of designs, explain its logic, a. Non-equivalent control group pretest only b. Non-equivalent control group pretest/posttest c. Cross-sectional

Random Assignment and Equivalence

If you randomly assign participants to groups, can you assume the groups are equivalent at the beginning of the study? At the end? Why or why not? If you cannot assume equivalence at either end, what can you do? Please explain.

SPSS Experimental Design Analysis

1. An experiment was conducted to study the effects of different types of background music on the productivity of bank tellers. Two factors were studied, tempo of the music (A; slow, medium, and fast) and the style of music (B; instrumental, or vocal). For each combination of the two factors 4 branches of the bank were randomly

Designing a study: research on new drug development

My example is this: I have been approached by a pharmaceutical company that has developed a new drug, which is supposed to be effective in the treatment of schizophrenia. Before I begin mass-producing the drug, the company wants to be sure that the new drug is more effective than the one they are currently producing. The company

Statistics: New Logo Focus Group

In order to select a new design logo, a company randomly selects 150 adults ages 21 to 35. They are asked to choose the most appealing logo from three different designs. I. What is the population? II. What is the sample? III. Is the study observational or experimental? (Justify your answer so I am able to follow you.) IV

Statistical analysis and write up of a journal article on pancreatic cancer

The article is: Adjuvant chemoradiotherapy and chemotherapy in resectable pancreatic cancer: a randomised controlled trial By: J P Neoptolemos, J A Dunn, D D Stocken, J Almond, K Link, H Beger, C Bassi, M Falconi, P Pederzoli, C Dervenis, L Fernandez-Cruz, F Lacaine, A Pap, D Spooner, D J Kerr, H Friess, M W Büchler for the

Analyze a Self-designed Fictitious Study

1. Conduct a descriptive data analysis that includes the following: a) a measure of central tendency b) a measure of dispersion c) at least one graph 2. Briefly interpret the descriptive data analysis. 3. Conduct the appropriate statistical test that will answer your hypothesis: regression analysis, single t-test, ind

week 3

Using the table below, compare and contrast the main differences between two quantitative research designs and two qualitative research designs. Document your answers with cited scholarly sources and include references for all citations. Quantitative Research Designs Compare and Contrast Differences Between Quantitative

Random Sampling in Healthcare

1. Why is random sampling done? 2. What are some downsides to random sampling? 3. How does the way in which samples are determined impact the validity of the data? 4. Using an example from the healthcare system, describe a case where it is possible that the way the sample was selected harmed the validity of the data.

Sample vs population; discrete vs continuous interval variables

Just a small explanation needed for each. 1 Sample vs. Population: The health study of North Trondelang County of Norway (HUNT) surveyed more than 60,000 people in a Norwegian county and reported that 'people who have gastrointestinal symptoms, such as nauseas, are more likely to have anxiety disorders or depression than peop

Types of Research Methodology used in the Social Sciences

Please help I do not even know how to really do this paper and what it requires I need to include examples of the types of methodologies that are available, for example: experimental design, correlational studies, case studies, and so forth.

Expense of a cohort study vs. case-control study

Why is cohort studies more expensive than case-control studies? I know one problem is cohort studies often must be followed up for a long period to determine whether the outcome of interest has developed and they are more expense than case-control studies. What other rationale explains why cohort studies are more expensive than

Research Design

Research Question What is the research question? If it is not stated, what would you say the research question is? Would you say that the question is stated broadly enough for a qualitative study? Study Design What qualitative method is used? In what way is the method used an appropriate one for this stu

Experimental design

You have been asked to develop a study of the effects of watching Sesame Street on childrens' gender role orientations, intelligence, or sociability (select one). (1) Describe how you would design the study using a preexperimental design (one shot case study, one group pretest-post test design, or static group comparison --


1. For the following studies, indicate whether or not a repeated-measures t test is the appropriate analysis. Explain your answers. a. A teacher is evaluating the effectiveness of a new computer training program for third-grade mathematics. One of the third-grade class gets regular instruction for 90 minutes each day. A seco

Multiple choice questions on design of experiments

For an independent-measures experiment comparing two treatment conditions with a sample of n = 10 in each treatment, the F-ratio would have df equal to __________. 18 19 1, 18 1, 19 A researcher reports an F-ratio with df = 3, 36 for an independent-measures experiment. How many treatment conditi

Create a research design

What is the breaking point for those criminals that will not return to old habits? And why do other criminals return so easily? Criminals can be rehabilitated successfully and without extreme strain to tax dollars; however, the system needs to be researched and changed in order to provide criminals with the assistance they need

Economic Case Study - Universal

Economics - Summary The economics involved in the make or buy issue were unusually complex. In 1982 the manufacturing facilities that were required to make a meaningful volume of semiconductors for Universal would have cost in excess of $50 million. There was concern about Universal's ability to run a high-tech semiconductor fa