science & study basics- overview
DESCRIPTION
Ecological Methodology. LEC- 01a Althoff. Science & Study Basics- Overview. Scientific Method: H O vs. H A Types of Studies: Experimental vs. Observational. EXPERIMENTAL. INTERPRETATION. ANALYSIS: Trends/Baseline. EVALUATION OF METHODS. - PowerPoint PPT PresentationTRANSCRIPT
Scientific Method: HO vs. HA
Types of Studies: Experimental vs. Observational
Science & Study Basics- Overview
Ecological Methodology LEC-01a Althoff
INVENTORY & MONITORINGEVALUATION OF METHODS
EXPERIMENTAL
ANALYSIS: Trends/BaselineINTERPRETATION
Scientific Method
Observation(s)
Question
Hypothesis
Prediction
Test:Experimental or
Additional observation
Test does _______support hypothesis:revise hypothesis or
pose new one
Test does _______hypothesis: make
additional predictions and test
them
Activity: Put these in proper order• Conclusion
• Experiment
• Hypothesis
• Observation(question)
• Theory
Some important terms
• _______ = sample unit left as “normal” or untreated
• _______ = sample unit that something “different” is done to it
• _______ = assumes no bias due to human subjectivity
• __________________ = independent variable• __________________ = dependent variable
Observational vs. Experimental Studies
• Observational: no controls (usually), trying to determine basics, learn patterns, trends, characteristics
• Experimental: control (usually), have basic knowledge of subject that enables one to “separate” into treatment groups
Hypothesis
• = null hypothesis….essentially says “no differences”
• = alternative hypothesis….essentially says “found differences”…with statisticalevidence to support that
Observational vs. Experimental Studies
• Observational: generally summarize data using _____________ statistics
• Experimental: determine if differences between treatments are “real” using _______________ statistics
Statistics • Descriptive statistics: central tendency: mean, median,
mode spread: range, variance, standard deviation, standard error relationship: correlation (Pearson, Spearman)
• Inferential statistics: parametric: t-test, F-test, Analysis of Variance (ANOVA), chi-squared non-parametric: sign test, Kruskal-Wallis test, Friedman test
• Models: Akaikae Information Criterion (AIC), Structural Equation Modeling (SEM)
Quail Eggs: Does Size Matter?• Not all eggs laid are the same….can vary by:
1) weight/mass2) yolk composition (protein & lipid
%)3) albumen composition (protein & water
%) 4) shell thickness
Quail Eggs: Key components
23
Pre-incubation Mid-incubation
Quail Eggs: Does Size Matter?• Normally take 23-24 days to hatch from start of
incubation
• Young born are __________…meaning they are “ready” to go (aka leave nest) within 6-24 hours after hatching
• Eggs must be kept at 99-100 oF (99.5 oF best) for the duration of the incubation period
• 3 ways for us to “check” on development: 1) _______ eggs (expect weight will decrease) 2) _______ eggs (expect air space to increase) 3) _______ eggs (expect “light”/”dark” areas)
Quail Eggs: Checking Egg Status• Weigh – using digital platform scale
Quail Eggs: Checking Egg Status• Float – in beaker of water Sink Semi-float Float
Quail Eggs: Checking Egg Status• Candling
The “Study” Design
Starting with 100+ eggs
Placing in incubator with egg turner
Basics….
• Overall, eggs pre-incubation weighed from________________ grams
• To have “clear separation” of small vs. large eggs, will consider only eggs weight
11.3 g or less as _________12.4 g or greater as ___________
• Response variable: hatch within 24 hours of first hatch (= H24)
_______ or less ____ or greater
Hypothesis & Statistical Test• H0 - No difference in H24 between small and
large eggs• HA - Difference in H24 between small and
large eggs• Evaluate using Chi-Squared (X2)
Hatch in H24
Small eggs (<11.3)(N = 28)
Large eggs (<12.4)(N = 31)