HS-PS4-2: Why Information Goes Digital
Also called NGSS HS-PS4-2 · Topic: Waves and Electromagnetic Radiation · Physical Science
The Official Wording
Evaluate questions about the advantages of using digital transmission and storage of information.
Clarification statement: Examples of advantages could include that digital information is stable because it can be stored reliably in computer memory, transferred easily, and copied and shared rapidly. Disadvantages could include issues of easy deletion, security, and theft.
NGSS Lead States, 2013 · Read it on nextgenscience.org · checked October 15, 2026
What HS-PS4-2 Means in Plain English
Students ask and judge questions about storing and sending information as digital data, the ones and zeros behind phones and computers. They weigh real advantages, like exact copies and fast sharing, against real drawbacks, like files that are easy to delete or steal.
The standard sets no extra limits, so discussion can cover noise, storage, security and privacy. It builds on MS-PS4-3, which shows digital signals travel more reliably, and connects to the wave technologies students explain in HS-PS4-5.
HS-PS4-2 I Can Statements
- I can explain how digital data stores information as ones and zeros.
- I can compare how noise affects analog and digital signals.
- I can weigh the risks of digital storage, like theft.
HS-PS4-2 Worked Example
A flashlight test that pits a brightness message against an on-off message.
Does a message sent as on-off pulses survive noise better than one sent as brightness levels?
Set It Up: A flashlight with a dimmer, a light sensor probe, sheets of wax paper, and a list of numbers from 0 to 7 to send.
- Send the number 6 as a brightness level, with 7 as full brightness.Sensor reading decodes as 6
- Put two sheets of wax paper in the path and send 6 again.Reading drops and decodes as 3
- Send 6 in binary as three timed flashes: on, on, off.Received 110, which is 6
- Send the binary flashes through the wax paper.Dimmer, but still clearly on or off: 6
- Relay each message through three students, who each resend what they received.Brightness drifts each time, binary arrives intact
Noise made the brightness message wrong, but the on-off message arrived exact through the wax paper and every relay.
Why it works: A digital receiver only has to tell on from off, so moderate weakening or noise does not change the bits, and each copy is perfect.
Common Mistakes with HS-PS4-2
Thinking digital means permanent
“Digital files last forever.”
Try this: Digital copies are exact, but drives fail, formats go out of date and one click can delete everything, so backups matter.
Confusing digital with wireless
“A radio signal is digital because it travels through the air.”
Try this: Digital describes how information is coded, as separate steps like ones and zeros. Wired or wireless signals can carry analog or digital information.
Listing only advantages
An answer about digital music that never mentions risk
Try this: Weigh both sides: easy copying also means easy piracy, and stored data can be hacked, lost or shared without permission.
Where HS-PS4-2 Fits
Practice HS-PS4-2
Quick Check
- Why can a digital song be copied many times without losing quality?
- Name one disadvantage of keeping photos only on a phone.
- A signal gets weaker on the way. Why is digital more likely to arrive correctly?