Non experimental transcript

Survey Development and Research Designs

Non-Experimental Research Designs

• Key non-experimental research designs include:

  • Correlation

  • Regression

  • Group Comparison

  • Causal Comparative Study

• Important distinction in terminology:

  • Causal vs. Casual: Emphasis on correct spelling (causal comparative focuses on cause-and-effect relationships).

Correlation

• Definition: Examines relationships between two variables to determine if they are related.

  • Example Question: Are two variables related?

• Characteristics:

  • Involves only two variables.

  • Focused on identifying the existence of a relationship.

Regression

• Definition: Explores how multiple variables are related to a single variable of interest.

  • Example Question: What combination of variables affects a particular outcome?

• Comparison to Correlation:

  • While both correlation and regression focus on relationships, regression typically involves one main variable of interest and several predictor variables.

• Practical Examples:

  • Motor skills, cognitive skills, and language skills—exploring how these may interact and affect each other.

Key Factors Related to Language Skills

• Motor Skills: Linked to expressive language; speaking requires motor activities.

• Cognitive Skills: Includes memory, attention, and pattern recognition which support language learning.

• Language Exposure: Direct interaction with caregivers results in better language acquisition; critical in early developmental stages.

  • Example correlation study might explore the impact of these factors on language skills.

Group Comparison

• Definition: Investigates differences in performance between two or more groups based on characteristics.

  • Example Question: Do two or more participant groups perform differently on a measure?

• Designs:

  • Often involves individuals with specific characteristics (e.g., language disorders) compared to a control group.

  • Can involve multiple groups, such as studying language development in ASD, GLD, and typically developing children.

Clinical Implications

• Understanding the factors affecting language skills is crucial for assessment and intervention planning in clinical settings.

• Knowing common characteristics can help set realistic expectations and guide assessments for children with developmental challenges.

Causal Comparative Studies

• Purpose: To determine if a certain variable (like premature birth) causes an effect (like communication disorders).

• Characteristics:

  • Compares groups (e.g., those with and without a history of premature birth) to explore potential causal links.

  • Cannot ethically manipulate variables, unlike experimental studies.

Understanding Causation vs. Correlation

• Correlation indicates a relationship but not causation. Examine underlying reasons for correlations; e.g., population growth increasing both road building and births.

• Important considerations:

  • Reciprocal relationships (e.g., parent language use vs. child language development).

  • Example: MLU (mean length of utterance)-based correlations between children and their parents.

Regression Studies

• Sample Question: Exploring the relationship between frequency of gestures at 12 months and vocabulary at 24 months.

• Important variables include predictors and measures.

• Options for design include cross-sectional or longitudinal.

Research Articles

• Review relevant literature on correlations between tools (like language samples) and assessment results to understand findings.

• Recognition of the significance of measures aids in evidenced-based practice and assessment accuracy.

Summary of Key Research Designs

• Prospective Design: Longitudinal follow-up from birth to age of interest (e.g., assessing language skills).

• Retrospective Design: Analyze historical data to find relationships (e.g., comparing premature infants and their language outcomes).

• Ensure control of confounding variables to isolate the main variable of interest for more reliable conclusions.