# Exercise 7. Modeling

###### tags: `exercise`

## Instructions

- Below are Problems which should all be achievable using the information from class. The Challenge will require you to find resources or answers on your own.
- **Please complete this assignment in groups of two** or three. Be sure to include the members of your group at the top of your answers.
- Create a HackMD note to share your answers to these prompts. Include your names. Copy the prompts, add your code and explanatory text and images. Use markdown formatting to distinguish the prompts from the code and explanatory text of your answers.
- Submit your answers by sharing the note with Dr. Angelini before Friday at dawn.

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Download the [curated version of the class bumble bee wing landmark data set](https://github.com/aphanotus/BI377.Morphometry/raw/refs/heads/main/curated.class.wing.landmarks.Rda) to answer the questions below.

The questions below will ask you to use modeling. Your answers should use the conventions for reporting statistical tests in the text of a journal article.

### Problem 1

Do the shapes of forewings vary meaningfully according to their size? Test this question using a generalized linear model created with `procD.lm`.

#### Challenge 1

What would be the appropriate null model for the one you just created? Can you interpret the meaning of that null model?

### Problem 2

Do the shapes of forewings vary meaningfully based on the species assignments given to the specimens? Test this question using a generalized linear model created with `procD.lm`.

#### Challenge 2

What proportion of variance remains unexplained by this model? How effective do you think the model is at describing the shape of specimens?

### Problem 3

We all digitized the same wing shapes. Test whether we digitized specimens in such a way that it influenced wing shapes in the dataset. (Think carefully about the model you should test.)

#### Challenge 3

Did the size of wings affect the way each of us recorded wing shapes? Construct a model (with some careful thought) and test it.

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**Quick Links** | [BI377 Moodle](https://moodle.colby.edu/course/view.php?id=33250) | [BI377 HackMD](https://hackmd.io/@ColbyBI377/landingpage) | [rstudo.colby.edu](https://rstudio.colby.edu/)

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