Science & Study Basics- Overview

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Science & Study Basics- Overview
Ecological Methodology LEC-01a Althoff Science & Study Basics- Overview Scientific Method: HO vs. HA Types of Studies: Experimental vs Observational

EXPERIMENTAL INTERPRETATION ANALYSIS: Trends/Baseline EVALUATION OF METHODS INVENTORY & MONITORING

Scientific Method Observation(s) Question Hypothesis Test does _______
support hypothesis: revise hypothesis or pose new one Test does _______ hypothesis: make additional predictions and test them Prediction Test: Experimental or Additional observation

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 statistical evidence 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/mass ) yolk composition (protein & lipid %) 3) albumen composition (protein & water %) 4) shell thickness

Quail Eggs: Key components
3 2 Pre-incubation Mid-incubation

Quail Eggs: Does Size Matter?
Normally take 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 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

Placing in incubator with
The “Study” Design Starting with 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 g or less as _________ 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)