Project Grade 4 Engineering & Design
A Sampling Pole for Thrushwater Creek: A Grade 4 Design Project
A four-session grade 4 project in which teams build and refine a pole that dips a water sample from four feet out over a creek without spilling or tipping.
Objectives
- Students will write a problem statement listing the sampling pole's targets and limits.
- Students will build a pole that reaches four feet and returns a measured sample.
- Students will change one part at a time to fix a failure they recorded.
- Students will present a final design with a budget sheet and a test result.
Vocabulary
Key words: sample, prototype, failure point, fair test, reach
Teacher overview
Teams design, build, and refine a pole that dips a cup of creek water from four feet away and brings it back upright and nearly full. The client is a fictional volunteer group that has been wading into the water to collect its monthly sample, which is slow work and risky on an icy bank. The targets and limits in the brief follow from that job. Testing happens indoors with a taped standing line and a tub of water, and the session 3 rule of changing one part at a time is what separates this from a craft project. The final deliverable is a working pole, a test sheet, a budget sheet, and a short demonstration.
Project Brief
Driving question: How can one person collect a cup of creek water from four feet away without stepping into the creek?
The client. The Thrushwater Creek Watch is a made-up volunteer group. Once a month its members collect a cup of water from the middle of the creek. A lab tests the sample. Right now a volunteer wades in to fill the cup. The bank is slippery. In winter it is icy. The group asked your class for a better tool.
What you are building. A sampling pole. It holds a cup at one end. A person stands on the bank and reaches out with it. The cup dips into the water, fills, and comes back. The cup must stay upright the whole way.
Your targets. Your pole must meet all four.
- Reach at least 4 feet past the standing line.
- Bring back at least 3/4 of a cup of water.
- Keep the cup upright from the dip to the bank, with no tipping.
- Work with one person holding it in two hands.
Your limits.
- You may spend 14 supply tokens or fewer.
- The pole must come apart into pieces no longer than 2 feet, so it fits in a backpack.
- No sharp metal points anywhere on the pole.
Price list. A dowel or paint stirrer costs 2 tokens. A cardboard tube costs 1 token. A binder clip costs 1 token. A rubber band costs 1 token. A 12-inch piece of duct tape costs 1 token. A plastic cup costs 2 tokens. One foot of string costs 1 token.
The test. Tape a standing line on the floor. Set a tub of water so the far edge sits 4 feet past the line. Keep both feet behind the line. Dip, lift, and return. Pour what you brought back into a measuring cup and write down the amount. Every team tests the same way.
What you turn in. A working pole. A test sheet with a row for every try. A budget sheet that adds up your tokens. A three-minute demonstration for the Creek Watch. In it, name the failure you fixed and show the test row that proves it.
Milestones
Session 1: define and sketch. Read the brief as a team. Write a problem statement in your own words. It must list all four targets and all three limits. Then draw two different poles. Label the handle, the joint, and the cup holder on each. Pick one to build first, and write one sentence naming the target that decided it. Output: a problem statement, two labeled sketches, and the reason for your pick.
Session 2: build and run the first test. Build your first pole. Stay inside 14 tokens and write each purchase down. Run the reach test three times. After each try, record the amount you brought back and what went wrong. Circle the one part that failed most often. Output: three test rows and a circled failure point.
Session 3: fix one part and test again. Change only the part you circled. You might stiffen the joint, move the cup holder, or shorten the handle. Keep the tub, the line, and the cup the same. Run three more tries. Compare the two sets of rows. Output: three new test rows and one sentence naming the single part you changed.
Session 4: final test and demonstration. Run one last set of three tries. Finish the budget sheet. Then give your demonstration to the Creek Watch. Show the pole working. Name the failure you fixed. Say which of your two first sketches you now think was the better idea, and why. Output: a final test row set, a budget sheet, and the demonstration.
From Water for Schools (waterforschools.org). This material is in the public domain (CC0) and may be copied, edited, and shared freely.
Rubric
| Criterion | Emerging | Developing | Proficient | Advanced |
|---|---|---|---|---|
| Problem statement | Lists fewer than four of the seven targets and limits | Lists most targets but leaves out the token limit or the backpack limit | Lists all four targets and all three limits in the team's own words | Lists all seven and adds a target the brief left out, such as working with cold hands |
| Pole performance | Pole does not reach 4 feet or returns almost no water | Pole reaches 4 feet but the cup tips or returns less than 3/4 cup | Pole reaches 4 feet and returns at least 3/4 cup upright on at least two of three tries | Meets every target on all three tries, and the team names the design choice that made it steady |
| Refining from tests | No failure point is recorded, or several parts change at once | A failure point is recorded, but more than one part changes between test sets | Exactly one part changes between test sets, and the team compares the two sets of rows | One part changes, the team explains why that part was the failure, and the test rows show the gain |
| Budget and demonstration | Token total is missing or above 14 with no correction | Token total is at or under 14 but is not itemized | Token total is at or under 14, itemized, and the demonstration shows one test row | Budget is itemized and the team explains a trade it made, such as spending on the joint instead of the handle |
Differentiation
Support
Give these teams a starter kit with the handle and the cup holder already joined, so the build begins at the part most likely to fail. Provide a test sheet with the columns filled in and the first row modeled. Shorten the reach target to 3 feet for sessions 2 and 3 and raise it to 4 feet only in session 4, so early tries end in a measurable result rather than a miss.
Extension
Ask these teams to add a fifth target of their own choosing and design to it, such as collecting the sample from 6 inches below the surface instead of at the top, which is closer to how real crews sample a stream. They should explain what changes in the tool when the cup has to go under and come back up closed, and test at least one way to keep surface scum out of the cup.
ELL supports
Label a full-size drawing of the pole with handle, joint, cup holder, and reach, and tape it where teams can point to it while talking. Demonstrate one full dip-and-return silently before any reading, then again while naming each part. Accept test-sheet entries written as numbers plus a sketch of what went wrong, and let the session 4 demonstration be mostly shown rather than spoken, with three labeled cards for the spoken part.
Extensions
Show students photographs of the extension samplers real monitoring crews carry and ask which parts of their own poles match and which parts the real tool adds, such as a bottle clamp that can be opened from the handle. Connect the work to why the sample has to come from moving water in the middle of the channel rather than from the quiet edge, and ask what that requirement would change about a pole built for a much wider creek.