what are the main features of a lab experiment
repeatability is the number one criteria for a experiment.
I'm not sure what you are seeking, but this might be helpful. Besides repeatability, the main feature involves control over many of the variables involved.
An independent variable is the potential stimulus or cause, usually directly manipulated by the experimenter, so it could also be called a manipulative variable.
A dependent variable is the response or measure of results.
Extraneous variables — other than the independent variable — potentially can affect the dependent variable, so they must be controlled. If possible, you try to keep them constant between the experimental and control group.
The experimental group receives the independent variable.
The control group is similar to experimental, except it does not receive the independent variable. Extraneous variables are balanced between experimental and control groups.
Types of experiments
1. Single blind gives the control group a placebo — a substance that is inert, it has no physical effect. Subjects don't know if they are in experimental or control group to reduce placebo effect, a change in behavior solely due to believing that you are getting the independent variable.
2. Double blind keeps both subjects and experimenter ignorant of group setup. Distribution of the independent variable and placebo is controlled by third party. This controls for experimenter bias and self-fulfilling prophecy. This means that experimenters with particular expectations are likely to consciously or unconsciously to bias the experiment and influence it to conform to their expectations.
As an example, suppose you want to find out if fluorides reduce dental cavities. You would find two groups, trying to control the extraneous variables. Extraneous variables are found by surveying previous research in the area. In this case, you would match the groups in terms of previous history of cavities, diet and dental hygiene habits including how and how often they brush their teeth.
The experimental group would get toothpaste with the independent variable, the fluoride, while the control group would not have the fluoride in their toothpaste. The toothpaste without the fluoride would be the placebo.
The dependent variable would be the number of cavities after participating in the experiment for a time. The dependent variable indicates the results, but it is not the results. At the end of the experiment, both groups could have no change in cavities or one of the groups could have a greater reduction in cavities. (Of course, if the fluoride increased cavities, you wouldn't want to use it.) All of these varied results would be indicated in terms of the dependent variable.
If only the subjects do not know who is getting the fluoride, it is a single blind experiment. If both the subjects and experimenter do not know, it is a double blind.
I hope this helps. Thanks for asking.
The main features of a lab experiment include:
1. Controlled variables: In a lab experiment, researchers systematically manipulate and control certain variables while keeping other variables constant. This allows them to isolate the effect of the manipulated variable on the outcome.
2. Randomization: Participants or samples are randomly assigned to different experimental conditions to minimize biases and ensure that the groups are comparable. This helps to establish the cause-and-effect relationship between the manipulated variable and the outcome.
3. Replication: Lab experiments are typically conducted multiple times to increase the reliability and validity of the findings. Replication involves repeating the experiment with different participants or samples to see if the same results are obtained consistently.
4. Independent and dependent variables: The independent variable is the variable that is manipulated or controlled by the researcher, while the dependent variable is the variable that is measured to observe the effect of the independent variable. The relationship between the independent and dependent variables is examined to draw conclusions.
5. Standardized procedures: Lab experiments require a standardized protocol to ensure consistency across different experimental conditions. This includes using the same equipment, instructions, and procedures for all participants or samples.
6. Data collection and analysis: Lab experiments involve collecting data on the dependent variable(s) and analyzing them statistically to determine any significant differences or correlations between the variables. This helps to draw conclusions and make inferences about the relationship between the variables.
To conduct a lab experiment, it is important to define clear research questions, design the experiment with appropriate controls and variables, recruit participants or obtain suitable samples, implement the experiment with standardized procedures, collect and analyze the data, and interpret the results in relation to the research questions.