BIOLOGY I Exploration & Discovery

Scientific Method: HO vs. HA

Types of Studies: Experimental vs. Observational

Bobwhite Quail Eggs: Does Size Matter?

Lecture/Lab01

Althoff

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

Lab handout: Activity 1• 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

• At _______ = assumes no bias due to human subjectivity

• _________ variable = independent variable• _________ variable = dependent variable

Observational vs. Experimental Studies

• Observational: __________ (usually), trying to determine basics, learn patterns, trends, characteristics

• Experimental: _________ (usually), have basic knowledge of subject that enables one to “separate” into treatment groups

Hypothesis

• HO = _______hypothesis….essentially says “no differences”

• HA = _________ 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:

___________________: mean, median, mode__________: range, variance, standard deviation, standard error_____________: correlation (Pearson, Spearman)

• Inferential statistics:_____________: t-test, F-test, Analysis of Variance

(ANOVA), chi-squarednon-parametric: sign test, Kruskal-Wallis test,

Friedman test

• Models: Akaikae Information Criterion (AIC), Structural Equation Modeling (SEM)

Quail Eggs: Does ______ 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

Quail Eggs: Does Size Matter?• Normally take __________ 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 (_____ 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 ______ Semi-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 from9.6 to 14.1 grams

• To have “clear separation” of small vs. large eggs, will consider only eggs weight

______g or less as SMALL______ g or greater as LARGE

• Response variable: hatch within 24 hours of first hatch (= _____)

Hypothesis & Statistical Test

• H0 - ____________in H24 between small and large eggs

• HA - _________ in H24 between small and large eggs

• Evaluate using _________________ (X2)

# ____ # ____

# ____ #____

Hatch in H24

Small eggs (<11.3)(N = 28)

Large eggs (<12.4)(N = 31)