3. a) What does it mean to manipulate a variable? b) What does it mean to control a variable? c) What is the difference between a controlled variable and a control group? a) To manipulate a variable is the ability to turn a potential cause on or off willingly. b) To control a variable is to make it so the variable cannot influence the experimental results.
* External validity/selection bias: the number of study participants and how participants are selected, with greater external validity assigned to studies with a larger number or participants who are randomly assigned to experimental conditions. * Generalization: the extent to which an experimental effect is observed beyond the treatment setting, under natural conditions, and maintained over time. Dissemination of Evidence-Based Practices in
3. Research and experimentation help to support a theory or prove that it has no foundation. The threats to internal validity include, history, maturation, testing, instrumentation, statistical regression, differential selection and experimental mortality. The threats to external validity include, reactive effects of testing, self-selection, reactive effects of experimental arrangements and multiple-treatment interference. To control or eliminate these threats, controlled experiments are done.
They might operate in one of two ways when it comes to research, either as a “dependent variable,” or “independent variable,” it is usually known by either letters or numbers---A variable is anything that has the ability to change or vary in characteristics or properties. A variable commonly represents the unknown if my thinking is on track An “independent variable” also known as “predictor” variable, is a variable that can be manipulated or changed. In an experiment in order to observe the effect on the dependent variable and it can stand on its own. The dependent variable is uncertain as its outcome is reliant on the reaction of the independent variable---this is why it is called a “dependent variable” because it is dependent upon the “independent” For equations such as y = 3x – 2, the dependent variable is the “Y,” which depends upon the value chosen for “x.” On most occasions the dependent variable is normally isolated on one side of the equation. With the above equation the independent variable is the “X”.
The reason for this is because in tests like these observed differences are usually due to chance differences in sampling. Meaning that, let’s say the p value is more than the significant level of what is being tested or if it’s less than what is being tested. If it is more the null hypothesis is rejected, and if it is less the null hypothesis is rejected in favor of an additional hypothesis. Which is more in the line of saying that it is accepted. The null hypothesis for this experiment was that there would be no changes in allele or genotype frequencies.
In the second scenario, qualitative research is utilized. It is research that focuses on the human experience through narrative descriptions and explanations of investigated phenomena, that emphasize non-numerical data (Polit & Beck, 2010). It is associated with a naturalistic paradigm in which subjectivity, inductive processing and contextualization are applied. These methods, in addition to the pursuit of in-depth understanding, serve as strengths of a qualitative design. However, researcher bias, time-consuming data collection and small sample sizes are its weaknesses.
Questions: * 1a) How is a mental response different from a measure of reaction time? Describe how reaction time relates to mental response. Simply providing definitions for each term is NOT a sufficient response. * A mental response is different from a measure of reaction time because a mental response is the act of perceiving set information and reacting to the stimulus in order to provide what we perceive is a correct response, whereas reaction time is the time that elapses between a stimulus and the response to it. For example, in this experiment, the mental response was perceiving the probe item and determining if it was one of the numbers in the memory set, and deciding on which button to press that corresponded with whether or not the item was present or absent.
Case studies allow for observations of unusual problems and allow for new techniques for therapy to be created. Disadvantages: It is said that biased observers record case studies and that they rely on subjective evidence (Axia College, 2003). Case studies do not fix everyone's problems. They do show a record of what a treatment worked on one patient, but this does not mean the same treatment will work on the next patient. Correlational Method: Advantages: This type of method is used to look for relationships between variables with three different possible results, a negative correlation, a positive correlation, or no correlation.
There must be criteria to go by that can prove whether the study is true or false. So we can start by making an observation and then posting a question to prove that observation true or false. Then, the hypothesis is used to make a guess on the outcome we think that the experiment will have. The third, and final step will be to test our observation and hypothesis and create data to come up with a conclusion for our study. The reason for having a hypothesis-based scientific study is because we do not know the outcome of something.
Bias occurs when there is a systematic error within the specific research and their findings. Bias can come from several sources, and it can also be classified into two categories: non-sampling error and sampling error. The non-sampling error includes non-response bias, sample selection bias, and systematic measurement error. Sample selection bias can be encountered within real property studies, which are often relied on observational samples like the occurrence of a comparable sale that cannot be assumed to have been a random event. Sampling error stems from the fact that a random sample can differ from the underlying population simply by