Core Concepts in Psychology and Research Methods

Mindsets and Learning Theories

Understanding Mindsets

• Fixed Mindset: Individuals believe their intelligence is static, "carved in stone," leading them to question their inherent capability.
• Growth Mindset: Individuals believe their knowledge and abilities are always expanding and growing through continuous learning.

Learning Styles and Limitations

Scientific studies indicate that individuals with different learning styles may perform better when material is presented in a specific way. However, if learning styles limit learning, it is often because individuals believe they are incapable of learning through other methods.

Sleep and Memory Consolidation

Relationship between Sleep and Learning: Sleep helps compile information into more memorable material. Information learned shortly before sleep is typically remembered better.

Cognitive Biases and Perceptual Phenomena

Self-Handicapping

A strategy used to protect the ego. The "handicap" provides an excuse for lack of success, allowing the individual to place fault on an ostensibly external factor instead of themselves.

Stereotype Threat

Anxiety experienced by a subject who fears that their identified group, or they personally, will be perceived negatively if they underperform in an activity where they are expected to excel.

Inattentional Blindness

The phenomenon where an individual, focusing intensely on one subject, becomes blind to changes or events occurring in the non-focused area.

Cognition, Metacognition, and Heuristics

Types of Cognition

• Cognition: The general process by which we process information.
• Metacognition: Higher-level cognition; thinking about the thought process itself.
• Automatic Cognition: Processing that does not require deliberate attention or effort.
• Controlled Cognition: Processing that requires deliberate attention and effort, performed intentionally while consciously aware of the action.

The Stroop Task

An experimental task where words naming colors are written in different colored ink on a screen, requiring the participant to state the actual color of the ink, not the word itself.

• Congruent Trials: The color of the word matches the actual word (e.g., the word "RED" written in red ink).
• Incongruent Trials: The color of the word is different from the word (e.g., the word "RED" written in blue ink).

Cognitive Heuristics

• Availability Heuristic: Judging the likelihood of events based on how easily examples come to mind (e.g., fearing flying more than driving because plane crashes receive more media coverage).
• Representative Heuristic: Making judgments about which category something belongs in, often based on stereotypes or prototypes.

Foundations of Empirical Research Methodology

Key Features of the Scientific Method

• Empirical Evidence: Data collected through direct observation or experiment, independent of argument or belief. Experiments must be reported in detail for verification.
• Objectivity: Minimizing all sources of bias and eliminating personal or subjective ideas.
• Control: Ensuring all extraneous variables are controlled to establish a clear cause (Independent Variable) and effect (Dependent Variable) relationship.
• Predictability: The goal of research findings should be the ability to predict future behavior.
• Replication: The ability for a particular method and finding to be reproduced with different or the same participants and/or on different occasions, yielding similar results.

Hypothesis Testing and Statistical Inference

Defining Hypotheses

Hypothesis Testing: A statement derived from theory, made at the start of an investigation, serving as a prediction.

• Null Hypothesis (H₀): The default position that the effect being sought does not exist.
• Alternate Hypothesis (H₁): The prediction that the hypothesized effect is correct.

Directional Hypotheses (Number of Tails)

A hypothesis can have a direction, known as the number of tails:

• One-Tailed Hypothesis (Directional): States that an effect exists and specifies the direction of that effect.
  • Example: Physical exercise increases mood. (The null hypothesis, "Physical exercise does not increase mood," is also one-tailed.)
• Two-Tailed Hypothesis (Non-Directional): States that an effect exists but does not imply a direction.
  • Example: Exercise has an impact on mood. (The relationship could be positive or negative.)

Research Validity

• Poor Validity: Occurs when the outcome measures something other than what the hypothesis intended.
• Internal Validity: Concerns whether the hypothesized variables are truly affecting the findings within the study (i.e., is what you think is happening really happening?).
• External Validity: The extent to which the results of a study can be generalized to other situations, environments, and populations outside the specific study setting.

Statistical Errors

• Type I Error (False Positive): Falsely rejecting the null hypothesis. This is a false scientific claim, concluding an effect is real when it does not exist in reality.
• Type II Error (False Negative): Falsely accepting the null hypothesis. This is a missed scientific discovery, concluding there is no effect when the effect is real.

Statistical Significance

The goal of hypothesis testing is to determine if observed differences are unlikely to be due to random variation. If so, the results are statistically significant.

The null hypothesis is rejected if the p-value is less than a predetermined threshold, known as the significance level (e.g., 0.05 or 0.01). For instance, if the significance level is 0.01 and the p-value is 0.008, the null hypothesis is rejected, and the result is statistically significant.

Experimental Design and Data Collection Methods

Experiment Design Fundamentals

Experiment design involves manipulating one aspect of the trial (the Independent Variable, IV) and measuring the impact on another aspect (the Dependent Variable, DV).

Primary Methods of Data Collection

1. Independent Groups Design

   Data is collected from two or more different groups of people.

   • Example: Comparing a control group that does not exercise with a treatment group that exercises regularly.

2. Same Subjects Design (Repeated Measures)

   Data consists of multiple measurements taken from the same group of participants.

   • Example: Measuring happiness levels before starting an exercise regimen and again after months of training the same group.
   • Note: Same subject designs generally have more statistical power and fewer sources of variation.

Randomized Controlled Trial (RCT)

The Randomized Controlled Trial (RCT) is considered the gold standard of clinical trials. It combines both design types by having pre- and post-measures for both a control group and a treatment group.

Statistical Test Models

• Parametric Test Model: Makes specific assumptions about the nature of the underlying data distribution.
• Non-Parametric Test Model: More general; does not rely on specific distributional assumptions.

Sampling Techniques and Population Representation

Key Definitions

• Target Population: The total group of individuals from which the sample might be drawn.
• Sample: The specific group of people who participate in the investigation.
• Generalizability: The extent to which research findings can be accurately applied to the larger target population.

Methods of Sampling

1. Random Sampling

   Every individual in the target population has an equal chance of being selected.

   • Advantage: The sample should be highly representative of the target population, minimizing sampling bias.
   • Disadvantage: Very difficult to achieve due to constraints of time, effort, and money.

2. Stratified Sampling

   The researcher identifies different subgroups within the target population and calculates the proportions needed for the sample to be representative of those subgroups.

   • Advantage: The resulting sample is highly representative of the target population.
   • Disadvantage: Can be complex and time-consuming to execute accurately.

3. Opportunity Sampling (Convenience Sampling)

   Selecting people from the target population who are available at the time and willing to participate.

   • Advantage: Quick and easy.
   • Disadvantage: Highly biased.

4. Systematic Sampling

   Choosing subjects in a systematic (orderly or logical) way from the target population, such as selecting every nth participant on a list.

   • Method: Divide the population size by the desired sample size to determine n.
   • Note: Should provide a representative sample, but can be costly.

Behavioral Psychology and Conditioning

Operant Conditioning Concepts

Operant Conditioning: A type of learning where the outcome behavior is a new behavior established through reinforcement or punishment.

• Differential Reinforcement: Implementing reinforcement only for the appropriate response (the desired behavior) and applying extinction (withholding reinforcement) to all other responses.
• Shaping: The differential reinforcement of successive approximations toward a target behavior. Small reinforcements are given for minor tasks along the way, and a bigger reinforcement is given once the target behavior is achieved.
• Satiation: A state where more of a reinforcer is required to achieve the same effect, often due to overuse.

Reinforcement Schedules

• Positive Reinforcement: The addition of a desirable stimulus following a behavior to increase the likelihood of that behavior occurring again. (Note: This type of reinforcement can be delivered on various schedules, including unscheduled/variable ones.)
• Fixed Ratio Reinforcement: Reinforcement based on a fixed ratio of behavior to reinforcement (e.g., being paid by commission after selling a set number of items).
• Interval Reinforcement: Reinforcement based on a fixed or variable amount of time (e.g., receiving an hourly wage).

The ABCs of Psychology

The fundamental components of psychological experience:

• A: Affect (Feelings/Emotions)
• B: Behavior (Actions)
• C: Cognition (Mental processes such as thoughts)