← DS-100 · Data Speak Louder than Words

Style Guide for Written Work

Formatting, citation, and AI-attribution requirements for all written submissions — part of the communication score on rubric-graded work.

All written submissions — project reports, written responses in assessments, and any narrative text in notebooks — must follow these guidelines. Spelling, grammar, and style compliance are part of the communication score on all rubric-graded work.

Typography

Font: Open Sans, Calibri, or Montserrat. Use a single font throughout; do not mix typefaces.

Size: 11 pt body text. Headings scale up from body (see Headings below).

Line spacing: Single (1.0) or tight (1.15). Do not use 1.5 or double spacing.

Paragraph spacing: Use your word processor’s paragraph spacing setting (Before/After) to add space between paragraphs. Do not press Enter twice to create blank lines between paragraphs.

Alignment: Left-aligned. Do not justify text.

Indentation: No first-line indent on paragraphs.

Periods: One space after a period, not two.

Headings

Use your word processor’s built-in heading styles (Heading 1, Heading 2, etc.) rather than manually bolding or enlarging text. This ensures consistent formatting and allows automatic table of contents generation.

Recommended heading sizes (relative to 11 pt body):

LevelUseSize
Heading 1Report title or major section16 pt, bold
Heading 2Subsection13 pt, bold
Heading 3Sub-subsection (use sparingly)11 pt, bold

Do not skip heading levels. Do not use heading styles for emphasis within a paragraph — use bold or italic instead.

Figures and Tables

Every figure and table must have:

  • A number: Figure 1, Table 1, etc., numbered sequentially throughout the document.
  • A caption: one or two sentences directly below the figure or above the table describing what it shows and what the reader should notice.

Caption format: Figure 1. Caption text in sentence case.

Refer to every figure and table in the body text before it appears (e.g., “Figure 2 shows the distribution of prices across neighborhoods.”). Do not include a figure without discussing it.

Code and Technical Terms

Inline code, variable names, function names, and file names appear in monospace font.

Code blocks (multi-line) use a monospace font, left-aligned, with no additional indentation beyond the block itself.

Do not put code in footnotes.

Lists

Use bulleted lists for unordered items; numbered lists for steps or ranked items.

List items are parallel in structure: all fragments or all complete sentences, not mixed.

Do not end list items with semicolons. End each item with a period if items are complete sentences; no punctuation if they are fragments.

Avoid lists longer than 6–7 items; consider grouping or prose instead.

Citations

Follow the Chicago Manual of Style, 17th edition. For the quick reference, see the Chicago-Style Citation Quick Guide.

Cite all of the following:

  • Data sources (dataset name, provider, access date)
  • External code or libraries beyond standard imports
  • Direct quotations and paraphrased ideas from any source

When in doubt, cite it.

AI Attribution

This course uses the AI Attribution model. Every graded submission that involved an AI tool must include an attribution line declaring your level of involvement:

LevelMeaning
AI-AAI provided suggestions or lookup; you wrote and decided everything
AI-EAI drafted or transformed content; you substantially revised and own the result
AI-CYou and AI iterated together; you directed, reviewed, and take responsibility
AI-GAI produced the primary content; you reviewed and chose to submit it

Place the attribution line at the end of your submission:

AI Attribution: AI-C — Used Claude (claude.ai) to draft the introduction; revised substantially and verified all claims against the dataset.

One line per AI tool used if you used more than one.

Unattributed AI use is treated the same as uncited copying. AI-G on project work will trigger a conversation about whether the work meets the course’s individual understanding requirement.

General Writing

Write in complete sentences. Avoid bullet-point summaries as a substitute for prose analysis — bullets are for lists, not for argument.

Use active voice where possible. Prefer “We filtered rows where price was missing” over “Rows where price was missing were filtered.”

Be precise. “The data shows a trend” is vague. “Median price increased by 12% from 2020 to 2023” is precise.

Avoid hedging phrases that add length without meaning: “it is worth noting that,” “it is important to mention,” “in conclusion,” “as previously stated.”

Proofread before submitting. Spell-check does not catch wrong words used correctly (“their” vs “there,” “affect” vs “effect”).

Anything not covered here follows the Chicago Manual of Style, 17th edition.