Reliability validity and representative sample in

Precision and accuracy Validity [3] of an assessment is the degree to which it measures what it is supposed to measure.

Reliability validity and representative sample in

Generalizability Only schools that randomly selected students, or surveyed students in randomly selected classrooms, are part of the national databases.

Reliability validity and representative sample in

However, the generalizability of the three ACHA-NCHA Pilots and the Spring database was evaluated by comparing the results to other surveys of the same population that have been sampled to represent all students in the United States. Reliability and Validity Analysis comparing relevant percentages with nationally representative databases, performing item reliability analyses comparing overlapping items with a nationally representative database, conducting construct validity analyses comparing ACHA-NCHA results with a nationally representative database, and conducting measurement validity comparing results of the ACHA-NCHA with a nationally representative database.

The data sets used for evaluation of reliability and validity are: The analyses employed different national databases, covered different approaches, and utilized different statistical procedures to accomplish the evaluation.

The answer would be no even in light of the consistent and divergent means of demonstrating consistency and replication. It is simply a set of schools with which one can compare data. This in turn helps in the decision-making process for planning programs and understanding the extent of health as well as unhealthy behavior that occurs on campus.

A brief description of each data set used for evaluation of reliability and validity is provided below. National College Health Risk Behavior Survey, CDC The NCHRBS, developed by the Centers for Disease Control and Prevention in collaboration with representatives in academia, national health organizations, and federal agencies, was a nationally representative sample conducted in of undergraduate college students aged 18 or older.

Risk behaviors associated with injuries, the consumption of alcohol, drug and tobacco usage, sexual behaviors and physical inactivity were assessed.

There was an adequate representation of minorities, sex, and age groups. Sampling was conducted at both two- and four-year institutions of higher education.

Sixteen schools were dropped due to low response rates.

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The remaining schools were located in 39 states. They represent a cross section of U. The schools were stratified by size less then 5,; - 10,; 10, or more and location urban or suburban and rural. The self-administered instrument surveyed students regarding alcohol, tobacco, drug use, student life-style and demographics.

United States Department of Justice: The study is a nationally representative sample of 4, women who were attending 2- or 4-year colleges or universities during fall Schools included in the sample had at least 1, students. The sample was stratified by the size of the total student enrollment 1,; 2,; 5,; 20, or more and school locations urban, suburban and rural.

Schools were randomly chosen using a probability proportional with the size of the total female enrollment. A second pilot was conducted in the spring of at 10 campuses.

The combined sample size was 3, Seven campuses participated with a sample size of 3, One school used a web-based surveying method. Reports of the results have been mailed to each participating school. For the purpose of this study and the formation of the reference group database, only those institutions that used a random sampling technique were included in the analysis, yielding a final data set consisting of 16, students on 28 campuses.

The vast majority, 27, were 4-year institutions. School size varied, with 1 school having less than 2, students, 2 schools 2,, 7 schools 5,, 10 schools between 10, and 8 schools 20, or more.Test-retest reliability is a measure of reliability obtained by administering the same test twice over a period of time to a group of individuals.

The scores from Time 1 and Time 2 can then be correlated in order to evaluate the test for stability over time. Validity: Defined. The term validity has varied meanings depending on the context in which it is being used. Validity generally refers to how accurately a conclusion, measurement, or concept.

Reliability vs. Validity Essay. Reliability vs - Reliability vs. Validity Essay introduction. Validity In this paper, I intend to evaluate whether the following websites are reliable and valid as sources of documentation to be used in research assignments.

Alpha Reliability Sport psychologists often produce a variable by effectively averaging the scores of two or more items from a multi-item questionnaire or alpha reliability of the variable is derived by assuming each item represents a retest of a single item.

For example, if there are five items, it's as if the five scores are the retest scores . Free Sample Questions.

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These questions are also included in our simulator 1. When it comes to Controlling for Threats to Internal Validity, there is a certain difference between RANDOM ASSIGNMENT AND RANDOM SELECTION.

- A sample is representative to the degree that the distribution of its characteristics parallels the characteristics of the study population - Basic threat to representativeness is bias Biased sample = distribution of characteristics varies systematically from study population.

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