3. Hypothesis Testing - 2L PP

# Using descriptive statistics which hypothesis do we

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Unformatted text preview: between Cypress and Birch? Using descriptive statistics: Which hypothesis do we reject? Let’s see our hypotheses again: •  Null Hypothesis: There will be no difference in the number of fruits produced by the plant grown with the fertilizer compared to the plant grown without the fertilizer. •  Alternative Hypothesis: There will be a difference in the number of fruits produced by the plant grown with the fertilizer compared to the plant grown without the fertilizer. Which hypothesis do we reject? Did we see a significant difference between the control and treatment group in terms of the number of fruits produced. -NO So, then, which hypothesis do we reject? - The alternative (because there was no difference between the control and treatment group) Average Number of fruits produced ASK THE QUESTION: 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Not fertilized Fertilized Can we “accept” a hypothesis? •  We do NOT accept hypotheses, –  If there are no significant difference (StDev bars overlap), results are CONSISTENT with the null hypothesis or the results SUPPORT the null hypothesis. Average Number of fruits produced rather we say: 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Not fertilized Fertilized Can we “accept” a hypothesis? &quot;   This is because… &quot;   If you didn’t find support for the alternative it could be because of other factors (the measurement or variable used to evaluate it was not the correct one, there was experimenter error, the experiment was poorly design, etc.), and if you re-evaluated the same hypothesis you might find different results &quot;   Hence, ‘accepting’ a hypothesis is TOO DEFINITIVE, especially with out many repeated tests What next? &quot;   Go back to your model &quot;   Develop new hypotheses &quot;   Always keep in mind other possible explanations &quot;   Design new experiments &quot;   It ne...
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