Homework 4


  • Submit your homework through Canvas before Thursday November 4th 11:59 pm. One submission per group.

  • If you want to use your 24-hrs extension, complete this Google form before the homework due date.

  • Remember to submit your write-up (only PDF extension) and your R script (.R or .Rmd). If both files are not submitted, the submission will be counted as incomplete until both files are received. Note: Submit an R scrip in .R, not in PDF

  • Use the templates provided below to guide you on how your submissions should look like.

  • No need to write long answers. Keep your answers short and precise, and address what is being asked (there are no additional points for answering something that is not being asked). Nonetheless, you need to be specific (e.g. it’s not enough to say “there is a confounding problem”; you need to explain why you think that and give a specific example).

  • Write a short paragraph at the end of the homework stating each members’ contribution to the assignment. You can indicate, for example, if everyone participated in the overall discussion of the different questions, but also if one particular individual took the lead on a specific question.


You can find Homework 4 here: Open HW4


Write-up Template

Rcode Template

Rmarkdown Template

Things to look out for

Besides the notes that have already been provided for previous assignments, I wanted to highlight certain aspects that you should be aware of for:

  • Keep your answers succint and pertinent: Most questions (or sub-questions) can be answered in one or two sentences, so keep things to the point (it makes it easier for you and for the graders). In particular, please do not answer things that are not being asked. For example, if the questions asks to estimate the causal effect of an intervention, do not interpret all coefficients. It makes it seem like you are not sure which one is the one you should be interpreting, so discounts will be applied in this case.

  • If there are sub-questions within a question, please label them: In order to facilitate grading, please label each sub-question you are answering, if there are multiple ones. I have included these labels on the questions as well to facilitate this.

  • Make sure you are using the right number of decimal places: I included notes on this for HW3, but please make sure that your p-values have more than one decimal place (remember that many times we want to assess whether a p-value is greater or less than .05, and that’s not possible to assess with just one decimal place). It depends on the context, but usually 2 or 3 decimal places are enough. In general, please do not provide answers with 5 or 6 decimal places. Such a level of precision is usually not necessary.

Answer Key

© Magdalena Bennett - licensed under Creative Commons.