VALIDITY & RELIABILITY

VALIDITY

Validity refers to the degree of appropriateness, correctness, truthfulness and accuracy of the study. In other words, the procedure shall measure what is intended to measure.

Types of Validity

• Content Validity - pertains to the degree to which the instrument fully assesses or measures the construct of interest. For example, an educational test with strong content validity will represent the subjects actually taught to students, rather than asking unrelated questions.

• Face Validity - is a component of content validity and is established when an individual reviewing the instrument concludes that it measures the characteristic or trait of interest. It requires a personal judgment, such as asking participants whether they thought that a test was well constructed and useful.

• Criterion Validity - assesses whether a test reflects a certain set of abilities. To measure the criterion validity of a test, researchers must calibrate it against a known standard or against itself.Example:One famous example is when Coca-Cola decided to change the flavor of their trademark drink.

RELIABILITY

The degree of consistency between two measures of the same thing.

The measure of how stable, dependable, trustworthy, and consistent a test is in measuring the same thing each time

Reliability is the extent to which an experiment, test, or any measuring procedure yields the same result on repeated trials.

4 TYPES OF RELIABILITY

1. Equivalency Reliability - is the extent to which two items measure identical concepts at an identical level of difficulty.

Also called alternate forms reliability, this type of reliability is used when there is an equivalent test (or another form of the same test) available. Both tests are administered and a correlation between the two is calculated.

2. Stability Reliability - sometimes called test, re-test reliability) is the agreement of measuring instruments over time. 

this method requires two administrations of the same test, separated by some time delay (a few days to a few weeks). The scores between the two tests are then correlated.

3. Internal consistency is the extent to which tests or procedures assess the same characteristic, skill or quality.

Measures how well one part of a single test correlates to another part of the same test.

• For example, a researcher designs a questionnaire to find out about college students' dissatisfaction with a particular textbook. Analyzing the internal consistency of the survey items dealing with dissatisfaction will reveal the extent to which items on the questionnaire focus on the notion of dissatisfaction.

4.Interrater reliability is the extent to which two or more individuals agree. Interrater reliability addresses the consistency of the implementation of a rating system

Statistical Treatment of Data

Basic Statistics

1. MEAN - The average of a set of n data x

M = ∑x

n

Standard Deviation

Deviation just means how far from the normal.

• Its symbol is σ (the greek letter sigma)

The formula is easy: it is the square root of the Variance. So now you ask, "What is the Variance?"

What is a Variance?

• The average of the squared differences from the Mean.

You and your friends have just measured the heights of your dogs (in millimeters):

The heights (at the shoulders) are: 600mm, 470mm, 170mm, 430mm and 300mm.

Find out the Mean, the Variance, and the Standard Deviation.

• Step 1: Mean =  600 + 470 + 170 + 430 + 300   =  1970  = 394

5 5

so the mean (average) height is 394 mm.

Step 2: o calculate the Variance, take each difference, square it, and then average the result:

Standard Deviation: square root of variance

= 147.32... = 147 (to the nearest mm)

21,704

And the good thing about the Standard Deviation is that it is useful. Now we can show which heights are within one Standard Deviation (147mm) of the Mean:

So, using the Standard Deviation we have a "standard" way of knowing what is normal, and what is extra large or extra small.Rottweilers are tall dogs. And Dachshunds are a bit short ..

Let’s try:Compute the Standard Deviation of the survey conducted

by the 4th yr. researchers on the level of customer satisfaction of a ABC Restaurant:

Out 30 respondents, this is what they gathered:Not satisfied = 4

Moderately satisfied = 7

Satisfied = 9

Very Satisfied = 6

Extremely Satisfied = 4

Mean = 6

Variance = (-2)2 + (1)2 + (3)2 + (0)2 + (-2)2

= 4 + 1 + 9 + 0 + 4

= 18

Standard Deviation = 18 = 9

Majority of the respondents are “satisfied” in the customer service of ABC Restaurant.

RECOMMENDATION

Summary, Conclusion and

Results of Summary

You should keep this section brief and identify the result with a general statement paragraph which it then followed by another paragraph that supports the evidence collected. You should avoid interpretation here and thus be objective about the results.

Discussion of Results

You should discuss the meaning of the results here, in brief, and highlight any important areas that you have identified. You should also look at the different things that the study means and how this is evaluated to the overall understanding in your thesis.

Recommendations

• These could be to your employer or to the academic community. You will want to keep this section brief and maybe to one paragraph or two, and explain what, from the research that has been conducted, there will be recommendations to the organizations or, if you are presenting to academia, then what further research should be conducted in the future

BIBLIOGRAPHY

APPENDICES

CURRICULUM VITAE

BibliographyAPA Style

• References. Alphabetize the entries in your list by the author's last name, using the letter-by-letter system (ignore spaces and other punctuation.) Only the initials of the first and middle names are given. If the author's name is unknown, alphabetize by the title, ignoring any A, An, or The.

Example: • Allen, T. (1974). Vanishing Wildlife of North America. Washington,

D.C.: National Geographic Society. • Boorstin, D. (1992). The creators: A history of the heroes of the

imagination. New York: Random House. • Nicol, A. M., & Pexman, P. M. (1999). Presenting your findings: A

practical guide for creating tables. Washington, DC: American Psychological Association.

• For dates, spell out the names of months in the text of your paper, but abbreviate them in the list of works cited, except for May, June, and July.

Example : (22 July 1999) or the month-day-year style (July 22, 1999)

Underlining or Italics?

Typewriter : Publications were underlined (typewriters have no italics)

Hand : Name of publication were underlined

Computer : Publications should be written in italics

Hanging Indentation

All APA citations should use hanging indents, that is, the first line of an entry should be flush left, and the second and subsequent lines should be indented 1/2".

Capitalization, Abbreviation, and Punctuation

• Capitalize only the first word of a title and subtitle. The exceptions to this rule would be periodical titles and proper names in a title which should still be capitalized. The periodical title is run in title case, and is followed by the volume number which, with the title, is also italicized.

• If there is more than one author, use an ampersand (&) before the name of the last author. If there are more than six authors, list only the first one and use et al. for the rest.

• Place the date of publication in parentheses immediately after the name of the author. Place a period after the closing parenthesis. Do not italicize, underline, or put quotes around the titles of shorter works within longer works

FORMAT EXAMPLE:Books :

Author's last name, first initial. (Publication date). Book title. Additional information. City of publication: Publishing company.

Example:

Allen, T. (1974). Vanishing wildlife of North America. Washington, D.C.: National Geographic Society.

Boorstin, D. (1992). The creators: A history of the heroes of the imagination. New York: Random House

ENCYCLOPEDIA & DICTIONARY:

Format:Author's last name, first initial. (Date). Title of Article. Title of Encyclopedia (Volume, pages). City of publication: Publishing company.

Example:

Bergmann, P. G. (1993). Relativity. In The new encyclopedia britannica (Vol. 26, pp. 501-508). Chicago: Encyclopedia Britannica.

Merriam-Webster's collegiate dictionary (10th ed.). (1993). Springfield, MA: Merriam-Webster.

Magazine & Newspaper Articles

Format:Author's last name, first initial. (Publication date). Article title. Periodical title, volume number(issue number if available), inclusive pages.

Example:

Harlow, H. F. (1983). Fundamentals for preparing psychology journal articles. Journal of Comparative and Physiological Psychology, 55, 893-896.

Henry, W. A., III. (1990, April 9). Making the grade in today's schools. Time, 135, 28-31.

Website or WebpageFormat:

Online periodical:Author's name. (Date of publication). Title of article. Title of Periodical, volume number, Retrieved month day, year, from full URLOnline document:Author's name. (Date of publication). Title of work. Retrieved month day, year, from full URL

Ex.

Devitt, T. (2001, August 2). Lightning injures four at music festival. The Why? Files. Retrieved January 23, 2002, from http://whyfiles.org/137lightning/index.html

References

Battery. (1990). Encyclopedia britannica. (pp. 100-101). Chicago: Encyclopedia Britannica.

Best batteries. (December 1994). Consumer Reports Magazine, 32, 71-72.

Booth, Steven A. (January 1999). High-Drain Alkaline AA-Batteries. Popular Electronics, 62, 58.

Brain, Marshall. How batteries work. howstuffworks. Retrieved August 1, 2006, from http://home.howstuffworks.com/battery.htm

Cells and batteries. (1993). The DK science encyclopedia. New York: DK Publishing.

Dell, R. M., and D. A. J. Rand. (2001). Understanding batteries. Cambridge, UK: The Royal Society of Chemistry.

Learning center. Energizer. Eveready Battery Company, Inc. Retrieved August 1, 2006, from http://www.energizer.com/learning/default.asp

Learning centre. Duracell. The Gillette Company. Retrieved July 31, 2006, from http://www.duracell.com/au/main/pages/learning-centre-what-is-a-battery.asp