Experimental Research -Research Biases

 What is Experimental Research?

Experimental research is a study that strictly adheres to a scientific research design.

It includes a hypothesis, a variable that can be manipulated by the researcher, and variables that can be measured, calculated and compared.

Most importantly, experimental research is completed in a controlled environment.

The researcher collects data and results will either support or reject the hypothesis. This method of research is referred to a hypothesis testing or a deductive research method

What is the Purpose of Experimental Research?

Experimental research seeks to determine a relationship between two (2) variables—the dependent variable and the independent variable. After completing an experimental research study, a correlation between a specific aspect of an entity and the variable being studied is either supported or rejected.

What type of Data are Collected in Experimental Research?

Data in experimental research must be able to be quantified, or measured.

Data collected could be acidity/alkalinity, area, circumference, density, electrical current/potential/resistance, force, growth (time, weight, volume, length/width), heat, humidity, light intensity, mass, pressure, sound intensity, temperature, time, velocity, volume or weight.

However, the entity should be carefully observed qualitatively, or described using words and photographs. How does the entity look, smell, sound, feel, and taste (when appropriate)? These types of observations help supplement the measurements taken throughout the experiment.

What Types of Experiments are Considered Experimental Research Projects?

•   Forensic Studies—Studying decomposition (an entomology study), damage to objects (a physics/engineering study), can be done in a controlled environment and be measured. eg., The Effect of _____ on_____” Studies—. All experimental studies look to determine how one thing affects another.
•          Product Effectiveness—If a specific aspect (active ingredients, size of crucial components etc…) of several products can be determined to be in different quality or quantity, this makes for a great experimental project. (For example the different levels of Ethyl Alcohol within antibacterial hand sanitizers.)
•        Microbiology—bacteria grow quickly, change in population is easily measured and therefore make for a good experimental study.

  

Research Biases We have got a hypothesis which is the first step in doing an experiment. Before we can continue, we need to be aware of some aspects of research that can contaminate our results. In other words, what could get in the way of our results in this study being accurate. These aspects are called research biases, and there are basically three main biases we need to be concerned with.

Ø  Selection Bias – occurs when differences between groups are present at the beginning of the experiment. 

Ø     Placebo Effect – involves the influencing of performance due to the subject’s belief about the results. In other words, if I believe the new medication will help me feel better, I may feel better even if the new medication is only a sugar pill. This demonstrates the power of the mind to change a person’s perceptions of reality. 

Ø    Experimenter Bias – the same way a person’s belief’s can influence his/her perception, so can the belief of the experimenter. If I’m doing an experiment, and really believe my treatment works, or I really want the treatment to work because it will mean so much for me, I might behave in a manner that will influence the subject.

 

Controlling for Biases After carefully reviewing a study and determining what might effect its results, we need to control for these biases.

Ø  To control for selection bias, most experiments use what’s called ‘Random Assignment’, which means assigning the subjects to each group based on chance rather than human decision.

Ø  To control for the placebo effect, subjects are often not informed of the purpose of the experiment. This is called a ‘Blind’ study, because the subjects are blind to the expected results.

Ø  To control for experimenter biases, we can utilize a ‘Double-Blind’ study, which means that both the experimenter and the subjects are blind to the purpose and anticipated results of the study.

Standardization

We have our hypothesis, and we know what our subject pool is, the next thing we have to do is standardize the experiment. Standardization refers to a specific set of instructions. The reason we want the experiment to be standardized is twofold.

First, we want to make sure all subjects are given the same instructions, presented with the experiment in the same manner, and that all of the data is collected exactly the same or all subjects.

Second, single experiments cannot typically stand on their own. To really show that are results are valid, experiments need to be replicated by other experimenters with different subjects. To do this, the experimenters need to know exactly what we did so they can replicate it.

To conclude, experiments should be objective. The views and opinions of the researcher should not affect the results of a study. This makes the data more valid, and less biased. If sufficient care is taken, experimental research is a good approach to obtain verifiable and proper results