Internal and External Validity

Internal Validity
Control over research condition is necessary to enable researchers to rule out plausible but incorrect explanations of results. There are several sources in internal validity. There are:-
- History
- Maturation
- Testing
- Instrumentation
- Statistical regression
- Experimental mortality
- Sample selection
- Demand characteristic
- Experimenter bias
- Evaluation apprehension
- Causal time order
- Diffusion or initiation of treatments
- Compensation
- Compensatory rivalry
- Demoralization

External Validity
Refers to how well the results of a study can be generalized across populations, settings, and time. The external validity of a study can be severely affected by the interaction in an analysis of variables such as subject selection, instrumentation, and experimental condition. Most procedures use to guard against external invalidity relate to sample selection. Cook and Campbell (1979) make three suggestions:
- Use random samples
- Use heterogeneous samples and replicate (repeat) the study several times
- Select a sample that is representative of the group to which the results will be generalised.


TUTORIAL ANSWERS.
QUESTION 1

Topic 1
To investigate students who browse the internet frequently are more exposed to the current news of the globe.

Internal Validity
Cause = frequency level
Effect = the amount of news collected less or more

Topic 2
To investigate the communication skills of youth nowadays among friends or family that were influence by the current media such as social network.

Cause = influence by the media (social network)
Effect = communication skills of youth nowadays among friends or family.


QUESTION 2

i) Prime time TV programmes are the most programs people likely to watch at the news in Malaysian TV3 from 8pm - 9pm. Usually programmes during the prime time are domestic drama, foreign drama series, movies and entertainment programmes.


ii) Students attitude in lectures tend to lost interest in focusing due to the boring conduct of lecture.
Student are easily distracted by their gadgets such as iPod, iPad, handphones, and laptops. 80% of student tend to concentrate to the lecture if it include element of humor in it.

iii) Addicted smart phone users tend to be more addicted  when 90% of their time in a day they spend it with their phone. By having more apps will span more attention towards their smart phones.



Written by: Faza Maisarah