Question

Answer the following:

1. Explain how a field's literature can be a source of significant research questions or problems.

2. List some important characteristics of literature reviews.

3. Explain the difference between one tailed hypotheses and two-tailed hypotheses

Answer 1

1. Reviewing the research literature means finding, reading, and summarizing the published research relevant to the uestion. The research literature in any field is all the published research in that field. Example The research literature in psychology is enormous—including millions of scholarly articles and books dating to the beginning of the field—and it continues to grow. Almost every primary research study begins with a review of the literature. The purpose of the literature review is to provide the reader with an overall framework for where this piece of work fits in the “big picture” of what is known about a topic from previous research. Thus, the literature review serves to explain the topic of the research and to build a rationale for the problem that is studied and the need for additional research.

The selection of a research problem can often be derived from an extensive and thorough review of pertinent research literature associated with the overall area of interest. This may reveal where gaps remain in our understanding of a topic.

the literature review is a story that explains the background to the problem the researcher (the writer) is exploring, and makes clear why this problem holds either theoretical or practical significance. The literature review sets the context of the research problem for the reader. From the literature review, the reader should understand why the particular research questions or hypotheses are addressed in the study, and how these research questions or hypotheses will expand knowledge in the given area.

2. characteristics of literature reviews are:

Organization: There are several options for organization of the review. Below are two common approaches.

• Big v: With this approach the review should flow from general to specific. This means that the writer presents information that is only generally related to the topic of the paper first, and as the literature review progresses one should build a case for the specific research questions or hypotheses in the study, so the literature review becomes more focused on the specific questions or hypotheses of the study.
• Variable Focused: In studies that examine relations among variables, the review may focus specifically on those variables and how they relate.

Relevance: This is a simple and easy to understand characteristic, but one that is often overlooked by writers. Anything cited in the literature review should be relevant to the study.

Omissions: As a writer, one should take care to provide all points of view on a given topic. This does not mean that a writer must include in the review every study conducted on a given topic; rather, this means that one makes an honest attempt not to conceal points of view on a topic that may not support the writer's position. Honesty and integrity are important in research, and not all researchers share these human characteristics.

Citations: Citations are the references a writer uses in the text. Below are a few characteristics to guide one when considering which studies to include in a review.

• Primary vs. secondary citations: A primary source of a citation is a study in which the author(s) are the ones who collected and analyzed the data or developed the idea, hypothesis, or theory. A secondary source is one that is removed from the primary author. It is best to use primary sources for citations simply because the primary author is less likely explain or report inaccurately his or her own work.
• Empirical research based citations: Empirical studies are those in which the authors collected data to address a question. Non-empirical sources include essays or position papers (author explains stance on something but without supporting data), theoretical papers, and non-empirical literature reviews.
• Recency of citations: To provide as complete picture of the current state of research in a given topic, it is necessary to ensure that citations cover a wide range of time periods.
• Agreement between citations and reference section: This characteristic appears to be relatively unimportant when consider against the other characteristics of a good literature review, but it is important.

Summary: This is typically a short paragraph or few sentences that summarize the literature review. In most written reports of research, the writer will provide a transition from literature review to research questions or hypotheses. The purpose of the transition is to help the reader see the connection between the literature review and the research questions or hypotheses.

3. Difference between one tailed hypotheses and two-tailed hypotheses are:

Two tailed:

First let’s start with the meaning of a two-tailed test. If we are using a significance level of 0.05, a two-tailed test allots half of our alpha to testing the statistical significance in one direction and half of our alpha to testing statistical significance in the other direction. This means that .025 is in each tail of the distribution of our test statistic.

When using a two-tailed test, regardless of the direction of the relationship we hypothesize, we are testing for the possibility of the relationship in both directions. For example, we may wish to compare the mean of a sample to a given value x using a t-test. Our null hypothesis is that the mean is equal to x.

A two-tailed test will test both if the mean is significantly greater than x and if the mean significantly less than x. The mean is considered significantly different from x if the test statistic is in the top 2.5% or bottom 2.5% of its probability distribution, resulting in a p-value less than 0.05.

One tailed:

let’s discuss the meaning of a one-tailed test. If we are using a significance level of .05, a one-tailed test allots all of our alpha to testing the statistical significance in the one direction of interest. This means that .05 is in one tail of the distribution of our test statistic.

When using a one-tailed test, we are testing for the possibility of the relationship in one direction and completely disregarding the possibility of a relationship in the other direction.

Our null hypothesis is that the mean is equal to x. A one-tailed test will test either if the mean is significantly greater than x or if the mean is significantly less than x, but not both. Then, depending on the chosen tail, the mean is significantly greater than or less than x if the test statistic is in the top 5% of its probability distribution or bottom 5% of its probability distribution, resulting in a p-value less than 0.05.

The one-tailed test provides more power to detect an effect in one direction by not testing the effect in the other direction.