Reliablity Validity of Research Tools 1

8/11/2019 Reliablity Validity of Research Tools 1

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RELIABLITY & VALIDITY OF

RESEARCH TOOLS

QUANTITATIVE & QUALITATIVE

STUDIES


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Essential to the effectiveness of any datagathering procedure.

Reliability is the degree of consistency that the

instrument or procedure demonstrate :-whatever it is measuring.

-it does so consistently.

Validity is that quantity of a data-gatheringinstrument or procedure that enables it tomeasure what it is supposed to measure.

ReliabilityandValidity


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Reliability is a necessary but not sufficient condition forvalidity. i.e. a test must be reliable for it to be valid, but a testcan be reliable and still not valid.

It is feasible through a variety of statistical treatments to

quantify the reliability and validity of psychological tests andinventories.

It is more difficult, though usually possible, to determinethese qualities for other data-gathering instruments orprocedures, such as observation, interview or the use of

questionnaire, in which response are more qualitative & yielddata that are not always readily quantifiable. One shouldattempt to improve the reliability and validity of theprocedures, but precise determination of the degree to whichare achieved is often elusive, generally in the case of validity.

ReliabilityandValidity

Continued


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4

Reliable

Valid

Not Reliable

Not Valid

Not Valid

Reliability Validity

Relationship ofReliabilityandValidity


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Determining Which Method Should Be

Used

Debates have been ongoing, tackling which method is better than theother. The reason why this remains unresolved until now is that, eachhas its own strengths and weaknesses which actually vary dependingupon the topic the researcher wants to discuss. This then leads us tothe question Whichmethod should be used?

If your study aims to find out the answer to an inquiry throughnumerical evidence, then you should make use of the QuantitativeResearch. However, if in your study you wish to explain further whythis particular event happened, or why this particular phenomenon isthe case, then you should make use of Qualitative Research.

Some studies make use of both Quantitative and Qualitative Research,letting the two complement each other. If your study aims to find out,for example, what the dominant human behavior is towards aparticular object or event and at the same time aims to examine whythis is the case, it is then ideal to make use of both methods.


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Quantitative Studies

Quantitative studies: has been defined as a numerical

method of describing observations of materials or

characteristics. When a defined portion of the material or

characteristic is used as a standard for measuring any

sample, a valid and precise method of data description is

provided.


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Types Of Quantitative Studies

Scientists distinguish among four levels of

measurement, listed & described in following.

1. A Nominal Scale

2. An Ordinal Scale

3. An Interval Scale

4. A Ratio Scale


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A nominal scale is the least precise method of

quantification.

A nominal scale describes differences between things byassigning them to categories-such as professors, associateprofessors, assistant professors, instructors or lecturers-and

to subsets such as male or females. Nominal data are counted data. Each individual can be a

member of the set have the same defined characteristic.such categories as nationality, gender, socioeconomicstatus, race occupation or religious affiliation provide

examples.

Nominal scales are non orderable, but in some situationsthis simple enumeration or counting is the only feasiblemethod of quantification & may provide an acceptable

basis for statistical analysis.

A Nominal Scale


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Sometimes it is possible to indicate not only that things

differ but that they differ in amount or degree.

Ordinal scale permit the ranking of items or individuals

from highest to lowest.

The criterion for highest to lowest ordering is expressed as

relative position or rank in a group:

1st,2nd,3rd,4th,5th,.nth.

Ordinal measures have no absolute values, and the realdifference between adjacent ranks may not be equal.

An ordinal scale


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An arbitrary scale based on equal units of measurementindicates how much of a given characteristics is present.

the difference in amount of the characteristic. possessed byperson with scores of 90&91 is assumed to be equivalent tothat between persons with scores of 60&61

The interval scale represents a decided advantage overnominal and ordinal scales because It indicates the relativeamount of a trait or characteristic. is present.

Its primary limitation is the lack of a true zero. It does not

have the capacity to measure the complete absence of thetrait and a measure of 90 does not mean that a person hastwice as much of the trait as someone with a score of 45.

An Interval Scale


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A ratio scale has the equal interval properties of aninterval scale but has two additional features:

the ratio has a true zero.

It is possible to indicate absence of a property.

Example: the zero point on a centimeter scale indicatesthe complete absence of length or height.

the numbers of the ratio scale have the qualities of realnumbers and can be added, subtracted, multiplied &

divided & expressed in ratio relationships. Example-5 grams is one half of 10 grams & 15 grams is

three times of 5 grams & on laboratory weighing scaletwo-1gram weights will balance a 2-grms weights.

A Ratio Scale


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Qualitative Studies

Qualitative research focuses on gathering of mainly verbal

data rather than measurements. Gathered information is thenanalyzed in an interpretative manner, subjective,impressionistic or even diagnostic.

1. Goal or Aim of the Research

The primary aim of a Qualitative Research is to provide acomplete, detailed description of the research topic. It isusually more exploratory in nature.

Quantitative Research on the other hand focuses more incounting and classifying features and constructing statisticalmodels.


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2. Usage

Qualitative Research is ideal for earlier phases ofresearch projects while for the latter part of theresearch project, Quantitative Research is highlyrecommended. Quantitative Research provides theresearcher a clearer picture of what to expect in hisresearch compared to Qualitative Research.


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3. Data Gathering Instrument

The researcher serves as the primary data gatheringinstrument in Qualitative Research. Here, the researcheremploys various data-gathering strategies, depending uponthe thrust or approach of his research. Examples of data-gathering strategies used in Qualitative Research areindividual in-depth interviews, structured and non-structured interviews, focus groups, narratives, content ordocumentary analysis, participant observation and archivalresearch.

On the other hand, Quantitative Research makes use oftools such as questionnaires, surveys, measurements andother equipment to collect numerical or measurable data.


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3. Data Gathering Instrument

The researcher serves as the primary data gatheringinstrument in Qualitative Research. Here, the researcheremploys various data-gathering strategies, depending uponthe thrust or approach of his research. Examples of data-gathering strategies used in Qualitative Research areindividual in-depth interviews, structured and non-structured interviews, focus groups, narratives, content ordocumentary analysis, participant observation and archivalresearch.

On the other hand, Quantitative Research makes use oftools such as questionnaires, surveys, measurements andother equipment to collect numerical or measurable data.


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4. Type of Data

The presentation of data in a Qualitative Research is in theform of words (from interviews) and images (videos) orobjects (such as artifacts). If you are conducting a

Qualitative Research what will most likely appear in yourdiscussion are figures in the form of graphs. However, if youare conducting a Quantitative Research, what will mostlikely appear in your discussion are tables containing data

in the form of numbers and statistics.


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5. Approach

Qualitative Research is primarily subjective in approach asit seeks to understand human behavior and reasons thatgovern such behavior. Researchers have the tendency tobecome subjectively immersed in the subject matter in thistype of research method.

In Quantitative Research, researchers tend to remainobjectively separated from the subject matter. This isbecause Quantitative Research is objective in approach inthe sense that it only seeks precise measurements andanalysis of target concepts to answer his inquiry


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ThankYou

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Reliablity Validity of Research Tools 1