Directions
- The floor: Section 1 of the classwork form, all six cases.
- Order: discussion form first, then Reading 2, then the classwork form. Do them in this order.
- Exit ticket: yes. It opens 20 minutes before the bell, pops up at 15, and locks your Chromebook until you submit.
- Submit the classwork form before the exit ticket pops up. You can reopen it and resubmit later.
- Past the floor: Section 2, then legitimate work for another class.
One Wrong Character
This reading describes three kinds of data in which a single changed character makes the information incorrect. Each example is presented once in its correct form and once with exactly one character changed.
A Bank Record and a Password
A bank record stores an account balance as a number, written to the cent. Suppose the correct record reads 1,250.00 dollars and one digit is changed, so the record reads 7,250.00 dollars. The record now reports 6,000 additional dollars that the account does not actually contain. NIST describes data integrity as the property that data has not been changed, destroyed or lost by accident or without permission. A bank record with one changed digit has lost its integrity.
A password follows the same principle. NIST guidelines require an authentication system to verify the entire password a person enters, without cutting off any part of it. If an account's password is Lake7river and a person types Lake8river, one character is different, and the sign-in fails.
A Line of HTML
The third example is a line of HTML from Picking Fruits, a student game built in September for the class arcade. The correct line is `<h1>Picking Fruits</h1>`, which makes the game's title a heading. In the changed line, the slash in the closing tag is missing, so it reads `<h1>Picking Fruits<h1>`. Without the slash, the browser interprets the second tag as the beginning of a new heading instead of the end of the first one.
The HTML standard tells the browser exactly what to do next. First, the browser closes the first heading. Then it opens a second heading, and every element after it on the page is placed inside that second heading. When both versions were tested on a plain page in the Chrome browser, the broken page still loaded and displayed no error message. However, the game's instruction "Tap the screen to start" appeared in large bold heading type instead of ordinary paragraph text.
Sources: NIST, Data integrity (n.d.); NIST, SP 800-63B-4 (2025); WHATWG, HTML Parsing (2026); Muggivan, HTML test (2026).
MC 1. (Case 1 · group-chat photo) You send a photo to a group chat, and the app sends a smaller copy that is optimized for chat. Is loss fine here, or is no loss allowed?
- Loss is fine here
- No loss allowed
CR 1. (Case 1 · reason) Give one reason for your answer to MC 1. Use one fact from Reading 2, the passage or Figure 1.
Write your answer in your lab notebook, labeled CR 1.
MC 2. (Case 2 · bank balance) A bank stores the balance of your savings account. Is loss fine here, or is no loss allowed?
- Loss is fine here
- No loss allowed
CR 2. (Case 2 · reason) Give one reason for your answer to MC 2. Use one fact from Reading 2.
Write your answer in your lab notebook, labeled CR 2.
MC 3. (Case 3 · song on a playlist) A song on your streaming playlist plays at the app's Normal quality setting instead of Lossless. Is loss fine here, or is no loss allowed?
- Loss is fine here
- No loss allowed
CR 3. (Case 3 · reason) Give one reason for your answer to MC 3. Use one fact from the passage or Figure 1.
Write your answer in your lab notebook, labeled CR 3.
MC 4. (Case 4 · password) A website stores the password for your school account. Is loss fine here, or is no loss allowed?
- Loss is fine here
- No loss allowed
CR 4. (Case 4 · reason) Give one reason for your answer to MC 4. Use one fact from Reading 2.
Write your answer in your lab notebook, labeled CR 4.
MC 5. (Case 5 · line of code) Your game is saved as HTML, and one of its lines is <h1>Picking Fruits</h1>. Is loss fine here, or is no loss allowed?
- Loss is fine here
- No loss allowed
CR 5. (Case 5 · reason) Give one reason for your answer to MC 5. Say what the browser did with the broken line in Reading 2.
Write your answer in your lab notebook, labeled CR 5.
MC 6. (Case 6 · video call) During a video call on a weak connection, the call app lowers the picture's resolution so the call keeps going. Is loss fine here, or is no loss allowed?
- Loss is fine here
- No loss allowed
CR 6. (Case 6 · reason) Give one reason for your answer to MC 6. Use Figure 1 or the passage's weak-wifi video example.
Write your answer in your lab notebook, labeled CR 6.
CR 7. (Trade-off 1 · song on a playlist) For the song in Case 3, say what was traded away and what was gained. Use the words file size and quality. Use one fact from the passage.
Write your answer in your lab notebook, labeled CR 7.
CR 8. (Trade-off 2 · video call) For the video call in Case 6, say what was traded away and what was gained. Use the words file size and quality. Explain how this is like the weak-wifi video in the passage.
Write your answer in your lab notebook, labeled CR 8.
DO NOT CLICK OPEN FORM FROM A LAB COMPUTER
Open the exit ticketThis opens during your class period.