BY: MIYA ILYAH AZMALAH RISKI INTAN PRATITIS AQIDATUL MUJADDIDAH EXPERIMENTAL RESEARCH

The Definition of Experimental Research is a systematic and scientific approach to research in which the researcher manipulates one or more variables, controls and measures any change in other variables.

The Goal of Experimental Research  The experimental research strategy is to establish the existence of a cause- and- effect relationship between two or more variables.  The experimental research is to enable researchers to control the research situation so that causal relationships between variables can be evaluated.

Types of Experimental Research Single variable design True- Experimental design Quasi- Experimental design Pre- Experimental design Pretest-posttest control group design Posttest only control group design Non-equivalent control group Time series One-short case study One-group, pretest- posttest Static group comparison

True Experimental Design Experimental design as considered true experiments when they employ randomization in the selection of their samples and control for extraneous variables and can predict confidently that the observed effect on the dependable variable is only due to the manipulation of independent variable.

Types of True Experimental Design Pretest-posttest control group design Posttest only control group design Exp. group Control group pretest treatme nt posttest pretest Random assignment Exp. grouptreatment Post- test Control group Post- test posttest

Quasi-Experimental Research Design Quasi-experimental design are generally used to establish the causality (effect of independent variable on dependent variable) in situations where researchers are not able to randomly assign the subjects to groups or for various reasons no control group is available for an experimental study.

Types of Quasi-Experimental Design Non-randomized control group design Time-series design Exp. group Control group pretest treatment Post-test Exp.group treatment

Pre-Experimental Research Classified depending on whether there is an involvement of one or two group, and whether groups are posttest only, or both are pretest and posttest.

Types of Pre-Experimental Research Design One-shot case design One-group pretest-posttest design Exp.group treatment Post-test Exp.grouppretest treatment Post-test

Static-group Comparison Design At least two groups are involved. After one group receives the treatment, all groups are posttested. the design has better control over most of the variables. Exp. group Control group treatment

Specific Terms Independent variable is controlled or set by the researcher Dependent variable is measured by the researcher An experiment is prescribed set of conditions which permit measurement of the effect of a particular treatment Hypothesis is represent specific restatement of the purpose of the study Randomization means that every subject has an equal chance of being assigned to experimental or of study subjects on a random basis. Manipulation the action of manipulating something in a skilful manner

Threat to Experimental Research External validity To how much result are generalized to target population. Internal validity Internal validity asks the question, “are the measurement I make on my dependent variable influenced only by the treatment, or are there other influences which change it?

External Validity Reactive Effect of Testing Treatment and Subject Interaction Testing and Subject Interaction Multiple Treatment Effect

Internal Validity History Maturation Testing Instrumentation Statistical Regression Experimental Mortality (Attrition) Selection-Maturation Interaction Experimental Treatment Diffusion Compensatory Rivalry by the Control group Resentful Demoralization of the Control Group Ex-Post Facto

History This refers to unplanned events that may occur during a study that impact the results unintentionally. Test subjects often have different experiences as the study progresses that may have an influence. For example, if doing a pretest and a post-test assessment at the beginning and end of a semester for two different classrooms to compare test results, one group may have a different classroom atmosphere or dynamic that influences the post-test results.

Maturation Subject change the course of an experiment. These change can be physical, mental, emotional, or spiritual. Perspective can change. The natural process of human growth can result in changes in post-test scores quite apart from treatment.

Testing Experiments that pretest the subjects may influence the performance of subjects on subsequent tests simply due to the fact that participants have already seen or completed the test before. People tend to perform better at any activity the more they are exposed to it.

Instrument If you use different tests for pre-and post- measurements, then the change in pre-and post-scores may be due to differences between the tests rather than the treatment. The best remedy is to use randomization and a post-test only design.

Statistical Regression Statistical regression refers to the tendency of extreme scores, whether low or high, to move toward the average on second testing. Subjects who score very high or very low on one test will probably score less high or low when they take the test again. That is, they regress toward the mean.

Experimental Mortality Experimental mortality, also called “attrition,” refers to the loss of subjects from the experiment. If there is a systematic bias in the subjects who drop out, then posttest scores will be are biased.

Selection-Maturation Interaction Interaction means the mixing or combining of separate elements. If you draw a group of subject from one school to serve as a control, you could well find— beyond the simple problem of selection differences (“Are the two groups equivalent?”)– a mixing of selection and maturation factors to compound the extraneous influence on your measurement.

Experimental treatment diffusion If subjects in the control group perceive the treatment as very desirable, they may try to find out what’s being done. Treatment diffusion can be controlled if experimental and control groups are isolated.

Ex-Post Facto 1. Studies pre-existing groups. smokers and non smokers 2. No treatment 3. This type of study often is called ex post facto research because it looks at differences “ after the fact;” that is, at differences that already exist between groups.

Compensatory Rivalry by the Control Group The members of the control group perceive that they are in competition with the members of the experimental group, they may get highly motivated to win the competition. If this happens and the research finds no difference between the average posttest scores of the control group, the lack of difference can be attributed to the control grup’s unusual motivation rather than to treatment effects.

Resentful Demoralization of the Control Group The members of the control group perceive that the members of the experimental group are receiving more desirable treatments, they may demoralize themselves so that in the posttest the control group may perform unusually lower than normal. If it turns out that there is a di-fferencein the posttest average scores between the experimental group and the control group, then the difference is not merely caused by the different treatments.

The Example of Title 1. The Influence of The Implementation of Mind Mapping Strategies on The Learning Achievement of Creative Writing in Terms of Students Creativity Research Problem: do achievement of creative writing have increased after implementing mind mapping strategies? (pre-experimental) Research Objective: the objective of this research is to measure the effectiveness of mind mapping strategies

The Example of Title 2. The Effectiveness of Using Reciprocal Technique on Students’ Reading Ability of Narrative Text Research Problem : is there any affectiveness of using reciprocal technique on students’ reading ability of narrative text Research Objective : to get empirical evidence about the effectiveness of reciprocal technique on students’ reading ability of narrative text