Midterm 1 Flashcards
What is a hypothesis?
An assertion of one possible state of the phenomenon or relationship under investigation. In other words, a proposed explanation for a question you are asking.
When is a hypothesis falsifiable?
A scientific hypothesis is falsifiable when it it is specific. A genuine test of a hypothesis is one that tries to refute it, not confirm it.
When is a hypothesis useless?
A hypothesis is essentially useless if it is consistent with every possible outcome. Rather, a hypothesis should be consistent with only a subset of possible empirical (observable) outcomes, and incompatible with others.
Why are testable hypotheses necessary?
This is because science is ever-changing, and refining. The scientific status of a theory is based on its falsifiability, refutability, or testability.
What is the purpose of a hypothesis?
It helps us generate simple models of the physical world, that allow us to predict phenomena, determine causes of phenomena, explain phenomena and control phenomena.
When is a hypothesis unfalsifiable?
- When no empirical evidence is obtainable
- When predictions are so vague that they can hardly fail
- When a hypothesis is upheld even though refuted by data, by introducing additional assumptions after the fact.
What is an operational definition?
A testable hypothesis must be operationally defined. An operational definition is a description of how a concept will be measured. Essentially, turning a concept into a quantity.
What is an example of an operational definition?
Happiness can be measured by how many times someone smiles in an hour, brain activity, or a self-report survey.
What is the purpose of an operational definition?
- They allow us to quantify and measure concepts.
- It makes sure variables are measured throughout the study.
- It allows us to communicate ideas to others.
What makes a good operational definition? VAAPORC
V - Validity (did your operational definition measure what
it actually intended to measure)?
A - Absence of bias
A - Acceptance in the scientific community
P - Practicality (something easy to measure)
O - Objective
R - Reliability
C - Cost (it is cost-effective)
Reliability and bias refer to____?
Refers to the difference between the measure and the “true” value of that variable. This difference is referred as systematic error.
What is bias?
Bias is the average error over many measurements.
What are the differences between hypotheses and predictions?
Hypothesis is framed as a statement, whereas a prediction is more related to the specific methodological details.
Hypothesis is often phrased in present tense, whereas predictions are often in the future tense.
Hypothesis is derived from a broader theory, whereas a prediction is quite specific.
What are the two main ways to assess operational definitions?
Reliability and validity.
Details about reliability
- Operational definition has to be based on concrete, observable behaviours.
- It must facilitate consistency/precision across measurements.
The more the variation, random error, and noise decrease ______.
Reliability
Details about validity
- Must be based on relevant behaviour
2. Facilitates the accuracy of measurements
The more the systematic error, and bias decrease _____.
Validity
A measurement is…….?
the true score + measurement error
Measurement error is…..?
systematic error + random error
What factors contribute to measurement error?
- Precision of the operational definition (lack of detail, subjectivity, and specificity)
- Error as a result of the measurement device.
- Human error (level of training, expertise, and attention level)
The more specific the operational definition, the more ______.
Consistent the measurements.
What does the r value represent?
It represents the correlation between the two variables.
What are the r values?
r>0, positive correlation
r<0, negative correlation
r = 0, no correlation