Essays PSYCH 350

Briefly describe each of the sources of new knowledge. What is the accepted role of each source of knowledge in modern scientific psychological research?

The sources of new knowledge are authority, intuition, empirical, and rational inductive

Intuition is knowledge based on how we feel about things, natural instinctive feelings about things to produce new knowledge.

Authority is knowledge gained from other people whose intuitions have been right often enough that we trust them to produce new knowledge.

Rational inductive is based on the process of a �proof � gather current knowledge, start with an axiom, build together things we already know to result in new knowledge

Empirical is to apply the scientific method � gather current knowledge, form a hypothesis about some new knowledge, gather data relevant to the hypothesis, test the hypothesis, the results are the new knowledge.

Contrast "proof" vs. "evidence." Which is preferred, what keeps us from obtaining it, and what do we do instead? What do we do to convince ourselves that our new knowledge is correct?

-proof is absolute certainty and evidence is probabilistic answers

-prefer proof

-proof requires rational inductive reasoning which requires a starting axiom that is absolutely true but this is rare in behavioral science we have to use evidence

-we use best possible methodologies, conduct replication and converging operations studies

Describe the research loop (be sure to briefly describe each stage). Tell the (3) different ways that it is applied and what we learn from that each type of application

-research loop is the steps in the scientific method

-library research to determine what we already know, hypothesis formation to guide the study, research design to figure out how to get results, data collection followed by data analysis to test RH, and finally draw conclusions about whether the hypothesis was correct or not

-test a novel hypothesis

-replication of the same research, ensure results are replicable

-convergent research, running different variations of the study and comparing the results

Briefly describe the kinds of validity we want our research to have and the dependent nature among them.

We would want measurement, internal, external, and statical conclusion validity. Measurement validity means that our data accurately reflects the behaviors and characteristics we are are trying to study. External validity means that our choices of participants, setting, and task/stimulus reflect the who, where and doing what we are trying to study. Internal validity means that we have controlled confounds so that we are studying the effects we are trying to study. Statistical conclusion validity means that we get the right empirical results from our study.

(statistical conclusion is dependent on chance and the other 3)

What is required to have a “truly random sample”? Is this often accomplished? When you are told that a sample is "random," what has usually been done?

To have a truly random sample you need a complete sampling frame, 100% return rate or complete substitution, and no attrition (participants dropping out as the study goes along)

This is rarely accomplished, usually because of limits in sampling frames and return rates.

Usually use purposive sampling frame, researcher selection, relatively good return rates, and participants who drop out are replaced

Compare and contrast IVs & confounds. Respond to the statement, “You only have to worry about confounds when you are testing a causal research hypothesis.”

IVs and confounds are both causal variables that have an influence to change participant�s values on the DV

The IV is the causal variable were are trying to study � we want to know the IV-DV relationship.

Confounds interfere with our study of the IV-DV relationship because, if there are confounds, we don�t know if the DV was caused by the IV, caused by the confounds, or by some combination.

Describe the variables that exist “before the study begins” and “after the study is completed” and how they are related. What determines what variables exist after the study is completed?

Before the study, we have an IV, DV, and potential confounds. After the study we still have our DV and our IV, but the potential confounds have become either constants, control variables, or confounding variables. The researcher determines whether potential confounds are controlled or become confounds that limit the internal validity and statistical conclusion validity of our results.

Distinguish between participant selection and participant assignment and tell the specific type of validity associated with each. Tell how “randomization” is applied to each and whether or not it is considered necessary.

-participant selection is who will be in the study
-participant assignment: who will be in which IV condition
-participant selection is related to population part of external validity and randomization is desirable but not required to run a true experiment
-participant assignment is related to the initial equivalence part of internal validity and random assignment is required to run a true experiment

Describe the two different characterizations of the relationship between internal validity and external validity. Which do you prefer and why? (You are free to prefer either characterization -- points are awarded based on the quality and completeness of you description of why you prefer that characterization. Be sure you articulately defend the opinion you state!)

Internal validity relates to the degree that the IV affects the DV, and that there are no (or few) confounds. External validity relates to the generalizability of the study to the outside world. One characterization is that there is a trade-off between the two, so when you have more internal validity you sacrifice external validity, and vice versa.

The precursor model is based on a primary emphasis on internal validity, causal interpretability and true experiments. The precursor model suggests that without internal validity and causal interpretability, external validity is unimportant (i.e., internal validity is a precursor to external validity

Can all causal research hypotheses be studied? Why or why not? (Be sure to give examples to support your answer!)

-no
-need random assignment, no confounds, and manipulation of IV which isn't always possible
-ethics, technology, and lack of resources are all limiting factors
- can't always randomly assign participants: ex: not ethical to randomly assign people to a brain damage condition, don't have the technology and it wouldn't be ethically sound to randomly assign gender
-even with a true experiment, you can't always maintain ongoing equivalence

Respond to each of these statements. “Unless you run a true experiment there is no way you can causally interpret your results.”

“Running a true experiment guarantees your results will be causally interpretable.”

The first statement is true!

Causal interpretability requires a true experiment with no confounds, so, without a true experiment you cant causal interpret your results

The second statement is false! For two reasons

random assignment doesn’t always produce initial equivalence of all subject variables

Sometimes confounds are introduced during IV manipulation, task completion or DV measurement which prevents ongoing equivalence

Suppose a colleague said to you, “Why even bother running non-experiments? We can’t get any useful information from them!” What seems to be the type of information this colleague thinks is the only useful kind? How should you respond to this statement?

Clearly my colleague believes that only causal knowledge is useful. I would remind my colleague that most of the information we apply in science, medicine, law and everyday life is associative. Associative information allows for accurate prediction, and prediction is often enough to support our scientific, medical, and societal decisions.

Describe the key steps in the research process, briefly describing the type(s) of validity “at stake” during the completion of each. (Be sure to identify those steps that are only necessary for testing causal research hypotheses).

-state research hypothesis, determine causal or associative
-participant selection: population part of external validity
-participant assignment: critical for causal RH and a true experiment, initial equivalence component of internal validity
-manipulation of IV: measurement validity, setting and task/stimulus parts of external validity, and ongoing equivalence part of internal validity which is essential for a causal RH
-measurement of DV: measurement validity, setting and task/stimulus part of external validity, and ongoing equivalence part of internal validity
-statistical analysis of data: statistical conclusion validity

Identify the attributes of a research study that do and do not directly influence the causal interpretability of the results. Also, tell the attributes of a study that can make it harder to maintain ongoing equivalence, and so, casual interpretability.

-two attributes directly influence causal interpretability: random assignment of participants to IV conditions and manipulation of IV by researcher

-four attributes do not: participant selection (external validity), setting (external validity), data collection method (measurement validity), and statistical analysis (statistical conclusion validity)

- field settings and longer studies make it harder to maintain ongoing equivalence