Biology 2244A/B Lecture Notes - Lecture 5: Null Hypothesis, Cluster Sampling, Statistical Hypothesis Testing

21 views8 pages

yellowgoldfish853

27 Apr 2019

School

Department

Course

Professor

For unlimited access to Class Notes, a Class+ subscription is required.

Document Summary

Part 1 of 4 - question 1 - research question 1 (14 marks, 3 parts) To address research question 1, you need to conduct a two-sample, independent samples t-test for difference in means. Please answer both questions 1a and 1b in the textbox below. Write your hypotheses in symbols. (ii) state the null hypothesis in words, using the context of the study: (5 marks; 4 sentences maximum) list the conditions for the two sample t-test for difference in means to be valid. For each condition, identify whether it is reasonable in our study and provide justification to support why or why not. In your answer, provide any r code(s) you used to assess these conditions. When listing conditions, be sure to write your answers in the context of this study (i. e. use the vocabulary of this study). a) Ha muf - mum < 0 null hypothesis is that female and male have the same 2d:4d ratio b)

Related Questions

Creat statistical test help please

Conduct an appropriate statistical test to see if there significant difference in the number of nutrition points collected for the DEAD (starved and killed) prey between high and low resource abundances. (Hint: you are testing for a significant difference between two population means.) Provide the complete outputs and highlight the appropriate P-value based on your hypotheses. Remember to evaluate your P-value and write out the conclusion.

---> What are some of the ecological reasons that may explain this result? Interpret your results in the context of optimal foraging theory and whether the prey is willing to take risks. (5 pts)

CLASS DATA OBTAINED BELOW:

 Mean nutrition points gathers vs. outcomes (alive & dead)

alive high	alive low	dead high	dead low
12		4	7
12		4	7
13		7	0
		6	7
		2	4
			2
			4
			3
MEAN alive high	MEAN alive low	MEAN dead high	MEAN dead low
37	0	23	34

4 According to a commercial, drinking water that has been blessed by Bill Nye the Science Guy improves your test scores. You think this is complete nonsense and want to disprove it. So you set up an experiment.

4a Would this be an observational or an empirical study?

4b To test it, for a total of 10 weeks, you take one test every week. Alternating weeks, you will drink regular water (control) and blessed water (treatment). How many replicas will you have?

4c What would be your null-hypothesis?

4d What would be your alternative hypothesis?

4e Name 3 possible confounding factors.

4f What is your independent variable?

4g Wat is your dependent variable?

4hs You set your a-level as always at 0.05, and do a statistical analysis to see if there is a difference in test scores between the two groups. The statistical analysis result is p=0.06 Is there a significant difference in test scores? Yes / No / Donât know

4i Based on the statistical analysis outcomes, does drinking blessed water improve test results? Yes / No / Donât know

4j 10 points A placebo effect is an improvement in a personâs perceived health from taking a non-active ingredient, presumably because of the belief that they are receiving a treatment helps that person to feel better. Your mind is a powerful thing and certainly can influence your health in real ways, so a placebo effect would include real improvements that come from âmind over matterâ as well as simple changes in perception. How can you avoid the placebo effect in this study?

ivoryraven299

Chose the correct answers on one through 15(plese help)

1.A research group hypothesizes that successful infection by HIVdepends upon the expression of FSH3, a human gene. They overexpressthis gene in T cells (Which HIV normally infects) so that FSH3protein levels are very high in these cells. In other T-cells, theymutate FSH3 so that none of its encoded protein is made. They thenmeasure HIV infection rate in the control, overexpression, andmutant T cells. The three cultures are otherwise grown in the sameway.

What is the independent variable(s) in this experiment? (Selectall correct answers)

		FSH3 protein levels
		The medium in which cells are grown
		The temperature at which cells are grown
		HIV resistance of cells

Question 2

Which arises from an error in a measurement or observation?

		Technical variability
		Biological variability
		Standard error
		Standard deviation

Question 3

Use the following description of an experiment to answer thenext question.

A research group hypothesizes that successful infection by HIVdepends upon the expression of FSH3, a human gene. They overexpressthis gene in T cells (Which HIV normally infects) so that FSH3protein levels are very high in these cells. In other T-cells, theymutate FSH3 so that none of its encoded protein is made. They thenmeasure HIV infection rate in the control, overexpression, andmutant T cells. The three cultures are otherwise grown in the sameway.

What is the control group(s) in this experiment? (Select allcorrect answers)

		The unaltered T cells
		The medium in which cells are grown
		The T cells in which FSH3 is mutated
		The T cells overexpressing FSH3

Question 4

How many of the following statements are true?

I. All papers have an abstract, methods, results, and discussionsection

II. The methods always follows the introduction

		0
		2
		1

Question 5

If scientific convention states that when a P value of less than0.05 is considered significant (in other words, the two groupsbeing measured are actually different), this means that: (Selectall correct answers)

		If you were to repeat the experiment 100 times, there would notbe a significant difference between the groups in 5 of theexperiments
		95% of all conclusions that state two groups are not differentbased on a 0.5% p-value threshold are false negatives
		The groups are actually not different from each other 95% of thetime
		5% of all conclusions that state two groups are different basedon a 0.5% p-value threshold are false positives

What information is typically found in the introduction sectionof a paper? (Select all that apply)

		The dependent and independent variables within the study
		Which areas of the field are not well understood and whatquestion the study addresses
		How the main question of the paper is related to other researchin the field.
		How previous work forms the basis for the current study
		The purpose of the study
		Details of the approaches used
		A summary of relevant related studies

Question 7

How can you judge for yourself whether the conclusions reachedin a paper are valid? (Select all that apply)

		Read papers of other authors studying the same question or areaof inquiry
		Determine if each hypothesis is supported by different types ofevidence/approaches.
		Consider closely whether the data actually both addresses andsupports the authorâs hypothesis.
		Examine the amount of data in the paper, and how long the paperis.
		Whether the authors find a mechanism, or exactly how on variableaffects another.
		Interpret the data for yourself without looking the discussion,then compare your interpretations to that of the authorâs.

Question 8

Where can you usually find the institutional affiliations (wherethey work) of the authors?

		Within the discussion
		In the acknowledgements section
		Below the authors list
		This is not usually included in papers

Question 9

Other than publishing primary research articles, what is themain way scientists disseminate their results?

		Lab meetings
		Personal correspondence
		Conference seminars
		Public lectures

Question 10

Use the following description of an experiment to answer thenext question.

What is the experimental group(s) in this experiment? (Selectall correct answers)

		Each group is its own control
		The T cells overexpressing FSH3
		The T cells in which FSH3 is mutated
		The unaltered T cells

grayclam130

Biology 2244A/B Lecture Notes - Lecture 5: Null Hypothesis, Cluster Sampling, Statistical Hypothesis Testing

Document Summary

Get access

Related Documents

Biology 2244A/B Lecture Notes - Lecture 4: Null Hypothesis, Australian Council Of Trade Unions, Alternative Hypothesis

Biology 2244A/B Lecture Notes - Lecture 9: Null Hypothesis, Statistical Parameter, Statistic

Biology 2244A/B Lecture Notes - Lecture 9: Qualitative Property, Null Hypothesis, Statistical Hypothesis Testing

Related Questions