Lecture 3 Flashcards
What is the definition of scientific method?
A set of systematic techniques used to acquire, modify, and integrate knowledge concerning observable and measurable phenomena.
The scientific method emphasizes observation and measurement.
What are the steps to scientific investigation?
- Formulate a hypothesis
- Study design
- Data collection
- Data analysis
- Reporting research findings
This systematic approach ensures clarity in the research process.
Define hypothesis.
A tentative statement about the relationship between two variables.
Hypotheses guide research by predicting outcomes based on specific conditions.
What are variables in a study?
Any measurable conditions, events, characteristics, or behaviors that are controlled or observed in a study.
Variables are essential for testing hypotheses.
What does observability mean in the context of scientific research?
A variable or phenomenon can be directly perceived or detected using the human senses or through instruments.
Observable variables are crucial for empirical studies.
What are the two types of observations?
- Direct Observation
- Indirect Observation
Direct observations involve immediate data collection, while indirect observations require inference.
What is a direct observation?
Observing the variable of interest without any intermediary steps.
Example: Measuring brain activity with EEG or MRI.
What is an indirect observation?
Assessing the variable through other observable factors or measurements.
Example: Measuring completion time in a maze to infer memory performance.
What is the difference between a hypothesis and a theory?
A hypothesis is a tentative prediction about a relationship between variables; a theory is a well-substantiated explanation supported by evidence.
Theories provide a framework for understanding behavior over time.
What is an operational definition?
Describes the actions or operations that will be used to measure or control a variable.
Operational definitions enhance specificity and reproducibility in research.
What does reproducibility mean in psychological research?
The ability of other researchers to independently replicate and obtain similar results when conducting the same experiment.
Reproducibility is essential for validating research findings.
What characterizes a testable hypothesis?
A hypothesis that can be subjected to empirical testing to determine if it is true or false based on observable evidence.
A testable hypothesis must also be falsifiable.
What are the advantages of case studies?
- In-depth investigation of individuals
- Well-suited for studying psychological disorders
- Provide compelling evidence for theories
However, they cannot draw causal conclusions.
What is a major disadvantage of survey studies?
Self-report data are often unreliable.
Surveys can yield large sample sizes but lack causal conclusions.
What is the role of control groups in experiments?
Control groups consist of participants who do not receive the special treatment, allowing researchers to isolate the effects of the independent variable.
This helps to identify true cause-and-effect relationships.
What is random assignment?
When all participants have an equal chance of being assigned to any group or condition in the study.
Random assignment minimizes confounding variables in experimental designs.
Define sampling bias.
When a sample is not representative of the population from which it was drawn.
Sampling bias can compromise the generalizability of research findings.
What are descriptive statistics?
Mathematical methods used to organize, summarize, and interpret numerical data.
Descriptive statistics provide an overview of data without making predictions.
What does central tendency refer to?
A single value that represents the typical score in a data set.
Measures of central tendency include mean, median, and mode.
What is the most basic type of statistic?
Descriptive statistics
Descriptive statistics simply describes the data mathematically and provides an overview of numerical data.
What does central tendency refer to?
A single value that represents the ‘center’ or typical value of a dataset
Central tendency summarizes the central or most common value in a set of data points.
What are the three common measures of central tendency?
- Mean
- Median
- Mode
How is the mean calculated?
By summing the scores and dividing by the number of scores
The mean is also called the ‘average’.
What is the median?
The score that falls exactly in the center of a distribution
What is the mode?
The most frequent score in a distribution
True or False: The average score is always the best way to describe data.
False
Example: In a company with nine employees making $10,000/year and one making $100,000/year, the mean does not accurately reflect the typical wage.
What does variability refer to in statistics?
How much the scores in a data set vary from each other and from the mean
What is standard deviation?
An index of the amount of variability in a set of data
What shape does a normal distribution typically take?
A symmetrical, bell-shaped curve
What does a normal distribution indicate about scores?
The majority of scores tend to fall close to the mean
What is a percentile?
The percentage of people who fall at or below a particular score
How much of a normally distributed sample falls within one standard deviation from the mean?
68% of all measurements
What does correlation quantify?
The degree of association or relationship between variables
What are correlation coefficients used for?
To measure the relationship between two variables
What is Pearson’s r?
The most common correlation coefficient
It indicates the strength and direction of a relationship between two variables.
What does a positive correlation indicate?
When one variable tends to increase as the other increases
What does a negative correlation indicate?
When one variable tends to increase as the other decreases
What does a correlation coefficient closer to 1 or -1 represent?
A strong correlation
What does a correlation coefficient closer to 0 suggest?
A weak or no correlation between the variables
