๐ฏ Comparison of reasoning paths from T-GRPO(Video-R1) and TW-GRPO
May 30, 2025 ยท View on GitHub
๐ฌ MMVU Mechanics 8.mp4
โ Question: Based on the measurements from the demonstration video, what is the approximate density of the stone in grams per cubic centimeter (g/cmยณ)?
๐ ฐ 2.0 g/cmยณ ๐ ฑ 2.2 g/cmยณ ๐ ฒ 2.5 g/cmยณโ ๐ ณ 2.7 g/cmยณ ๐ ด 3.0 g/cmยณ
๐ง Reasoning Chain Comparison: TW-GRPO vs T-GRPO
| Step | ๐ TW-GRPO (Ours) โ | โ T-GRPO (Baseline) โ |
|---|---|---|
| 1๏ธโฃ | ๐ฏ Goal identified: Compute density of the stone | ๐ฏ Goal identified: Compute density of the stone |
| 2๏ธโฃ | โ๏ธ Mass (in air): Extracted from video as 230g | Same: Mass = 230g |
| 3๏ธโฃ | ๐ Submerged (apparent) mass: Extracted as 138g | ๐ซ Ignored โ this critical data is not used |
| 4๏ธโฃ | โฌ๏ธ Buoyant force: 230g - 138g = 92g (equals water displaced) | ๐ค Assumes volume = 100 cmยณ without justification |
| 5๏ธโฃ | ๐ Volume from buoyancy: 92g / 1g/cmยณ = 92 cmยณ (using density of water) | Uses โ arbitrary volume value: 100 cmยณ |
| 6๏ธโฃ | ๐งฎ Density computation: 230 / 92 โ 2.5 g/cmยณ | 230 / 100 = 2.3 g/cmยณ |
| 7๏ธโฃ | โ Option match: Compares to options, selects C (2.5) โ correct and consistent | ๐ Begins redundant reasoning to reconcile 2.3 with available options |
| 8๏ธโฃ | โ | Says 2.3 is close to C; "verifies" multiple times |
| 9๏ธโฃ | โ | Despite analysis, ultimately selects D (2.7) โ contradicts own reasoning |
| ๐ | ๐ Logical structure: Fully grounded in physics + data โ consistent, closed loop | ๐ Broken chain: Assumptions, uncertainty, contradiction โ no valid closure |
๐ T-GRPO's Redundant Thinking (Detailed Breakdown)
| ๐ฃ๏ธ Behavior | ๐ญ Role / Problem |
|---|---|
| "Hmm, this value seems closeโฆ" | Attempts to rationalize incorrect assumption |
| "Let's verify by comparing with choicesโฆ" | Enters indecisive enumeration loop |
| "Oh, I see. The closest value to 2.3โฆ" | Tries to justify picking C despite flawed input |
"Final verification... Therefore the correct answer is C" โ <answer>D | ๐ฅ Critical failure: Final answer contradicts all prior logic |
๐ Summary
| ๐ Category | ๐ TW-GRPO | โ T-GRPO |
|---|---|---|
| ๐ Key data extraction | Accurate (230g / 138g) | Incomplete (138g ignored) |
| ๐งฉ Reasoning structure | Sequential, justified | Skips steps, inserts assumptions |
| โ๏ธ Use of physical principles | Yes (buoyancy, Archimedes' principle) | No (volume guessed) |
| ๐ Redundant reasoning | None | Yes โ due to internal inconsistency |
| โ Final answer consistency | Matches analysis (C) | Contradicts reasoning (says C, picks D) |
| ๐ Logical closure | Complete closed-loop reasoning | Broken loop with contradiction |
๐ Detailed Output
Click to view complete reasoning
โ T-GRPO (Baseline) โ:
๐ Initial Analysis:
Let me think about this for a moment. The problem involves determining the density
of the stone based on the given weight and volume data from the experiment.
First, let's recall the formula for density:
\[ \text{Density} = \frac{\text{Mass}}{\text{Volume}} \]
From the video, we know the following:
- The mass of the stone is 230 grams.
- The volume of the displaced water is 100 cmยณ (since the stone displaces 100 cmยณ of water).
๐งฎ Calculation Attempt:
Now, let's plug these values into the density formula:
\[ \text{Density} = \frac{230 \text{ g}}{100 \text{ cm}^3} = 2.3 \text{ g/cm}^3 \]
Hmm, this value seems close to one of the options provided.
Let's verify by comparing it with the given choices:
๐ Redundant Verification Loop:
A. 2.0 g/cmยณ - This is lower than our calculated value.
B. 2.2 g/cmยณ - This is also lower than our calculated value.
C. 2.5 g/cmยณ - This is slightly higher than our calculated value.
D. 2.7 g/cmยณ - This is significantly higher than our calculated value.
E. 3.0 g/cmยณ - This is even higher than our calculated value.
๐ Contradictory Conclusion:
Oh, I see. The closest value to our calculated density of 2.3 g/cmยณ is 2.5 g/cmยณ.
Therefore, the correct answer should be C.
Let's break it down one more time to ensure. The calculated density is indeed
2.3 g/cmยณ, which is very close to 2.5 g/cmยณ. So, the most accurate choice is C.
Final verification: The density of the stone is approximately 2.5 g/cmยณ,
which matches option C. Therefore, the correct answer is C.
๐จ Final Answer: <answer>D</answer> (contradicts reasoning)
๐ TW-GRPO (Ours) โ
๐ฏ Problem Understanding:
The video shows two key pieces of information: the weight of the stone when not
in water and its apparent weight when submerged. The initial weight of the stone
is given as 230 gm, which is the mass of the stone.
โ๏ธ Physics Application:
When the stone is submerged, its apparent weight decreases to 138 gm, indicating
that some force is acting upwards, which is buoyancy. The difference between these
weights gives us the buoyant force, which can be used to calculate the volume of
the displaced water, hence the volume of the stone.
๐งฎ Systematic Calculation:
The buoyant force can be calculated as the difference between the weight of the
stone in air and its apparent weight in water, i.e., 230 gm - 138 gm = 92 gm.
This buoyant force equals the weight of the water displaced.
Using the density of water (approximately 1 g/cmยณ), the volume of the stone is
approximately 92 cmยณ.
Now, using the formula for density, Density = Mass / Volume, we get
Density = 230 gm / 92 cmยณ โ 2.5 g/cmยณ.
โ
Final Answer: <answer>C</answer> (consistent with reasoning)
๐ฎ MVBench perception video_3824.mp4
โ Question: The person uses multiple similar objects to play an occlusion game. Where is the hidden object at the end of the game from the person's point of view?
๐ ฐ Under the second object from the leftโ
๐ ฑ Under the first object from the left
๐ ฒ Under the third object from the left
๐ง Reasoning Chain Comparison
| Step | ๐ TW-GRPO (Ours) โ | โ T-GRPO โ |
|---|---|---|
| 1๏ธโฃ Initial Setup | Notes 3 identical objects placed, one moved aside initially | Notes 3 objects and general shuffling |
| 2๏ธโฃ Key Action Recognition | Identifies that an object is moved aside before hiding occurs | Vaguely describes movement and placement of a "can", possibly misidentifying the object |
| 3๏ธโฃ Occlusion Interpretation | Realizes hiding occurs after one object is removed, under remaining object | Assumes the object is hidden without precise tracking of movement steps |
| 4๏ธโฃ Spatial Deduction | Infers the second object from the left now covers the hidden item | ๐ซ Incorrectly guesses the first object based on flawed assumptions about can placement |
| 5๏ธโฃ Re-check or Redundancy | Single logical pass, inference tied to specific movements | Repeats uncertain logic and asserts same flawed location |
| 6๏ธโฃ Final Answer | ๐ ฐ๏ธ (second object from the left) โ matches actual hiding spot | ๐ ฑ๏ธ (first object from the left) โ does not match video |
๐ Evaluation of Reasoning Quality
| ๐ Criterion | ๐ TW-GRPO | โ T-GRPO |
|---|---|---|
| ๐ฏ Accurate object tracking | Yes โ tracks displaced object and when hiding happens | No โ makes vague or incorrect references to movement |
| โฐ Temporal reasoning | Correctly sequences moveโhideโreplace | Misinterprets or oversimplifies time/order |
| ๐ Spatial deduction | Grounded in observed object positions | Assumption-based without visual justification |
| ๐ฏ Confidence vs uncertainty | Single-pass, high-confidence, justified answer | Redundant logic loop without adding clarity |
| โ Final answer correctness | Correct (A) | Incorrect (B) |
๐ Detailed Output
Click to view complete reasoning
โ T-GRPO (Baseline) โ:
๐ฏ Initial Setup Recognition:
Let me think about this for a moment. The person is playing an occlusion game
with three similar objects on a table. They shuffle these objects around, and
at some point, they hide one of them under one of the objects.
๐ค Uncertain Analysis:
First, let's break it down step by step. The person starts with the objects in
a certain order. Then, they shuffle them around, which means the positions of
the objects change. The key is to figure out which object was moved last and
where it ended up.
๐ซ Flawed Reasoning:
Wait, let's consider the sequence of actions. The person moves the objects around,
and at some point, they place the can next to the objects. This suggests that
the can might have been used to obscure the movement of one of the objects.
The person placed the can next to the objects, and the first object from the left
is the most likely candidate for being hidden.
๐ Redundant Verification:
Let's verify this. If the hidden object were under the second or third object,
the can would likely be covering it, but it's not. Therefore, the hidden object
is most likely under the first object from the left.
Let's break it down one more time to ensure. The person moved the objects around,
and the hidden object is most likely under the first object from the left.
โ Final Answer: <answer>B</answer> (incorrect)
๐ TW-GRPO (Ours) โ
๐ฏ Clear Observation:
The person starts by placing three identical objects on the table, then moves
one aside and places another object behind them.
๐ง Logical Deduction:
This suggests that they are playing a game where the hidden object is placed
under one of the objects. Since the person moved the first object aside and
then placed something behind the remaining two, it implies that the hidden
object could be under either the second or the third object from the left.
โ Confident Conclusion:
However, since the person's action of moving the first object aside indicates
that they might have intended for the hidden object to be under the second
object, it seems logical that the hidden object would be under the second
object from the left.
โ
Final Answer: <answer>A</answer> (correct)
๐ฒ CLEVRER video_validation 12176.mp4
โ Question: Without the sphere, what will happen?
๐ ฐ The cube collides with the blue cylinderโ
๐ ฑ The red object collides with the cubeโ
๐ ฒ The red cylinder and the blue object collide
๐ Updated Comparison: TW-GRPO vs T-GRPO
| Step | ๐ TW-GRPO (Ours) โ | โ T-GRPO (Baseline) โ |
|---|---|---|
| 1๏ธโฃ Object Identification | Identifies: red & blue cylinders, teal cubes, green sphere | Identifies the same set of objects correctly |
| 2๏ธโฃ Causal Assumption | Implicit or cautious: suggests proximity between red cylinder and cube | ๐ซ Incorrect: States green sphere causes red cylinder's motion |
| 3๏ธโฃ Sphere Removed Scenario | Suggests altered interactions might happen (e.g., red cylinder behavior may change) | Based on wrong premise: assumes red cylinder continues to move without sphere |
| 4๏ธโฃ Inferred Outcome | Predicts plausible events (red cylinder may hit cube) | Predicts red-blue cylinder collision, relying on false causality |
| 5๏ธโฃ Answer(s) Chosen | ๐ ฐ๏ธ, ๐ ฑ๏ธ โ reasonable interactions grounded in object proximity and motion | ๐ ฑ๏ธ, ๐ ฒ โ includes red-blue collision, derived from flawed counterfactual logic |
| 6๏ธโฃ Internal Consistency | Reasoning consistent, cautious, aligned with visual evidence | Contradicts video: green sphere is not a causal agent, yet treated as one |
๐ Summary
| ๐ Category | ๐ TW-GRPO | โ T-GRPO |
|---|---|---|
| ๐๏ธ Object recognition | Correct | Correct |
| ๐ Causal reasoning | Ambiguous but not wrong | Incorrect (reversed causality) |
| ๐ค Counterfactual logic | Conservative ("if sphere is gone...") | Invalid (relies on wrong premise about the sphere's role) |
| ๐ฏ Prediction accuracy | Matches visible possibilities (A, B) | Predicts incorrect outcome (C) |
| ๐งฉ Logical coherence | Sound chain of reasoning | Breaks due to false cause โ wrong effect |
| ๐น Alignment with video | Mostly aligned | Contradicts direct visual evidence |
๐ Detailed Output
Click to view complete reasoning
โ T-GRPO (Baseline) โ:
๐ฏ Initial Setup Recognition:
Let's break down the scenario step by step:
1. **Initial Setup**: There are four objects: two cubes, one green sphere, and two cylinders (blue and red).
2. **Sphere's Role**: The green sphere is currently interacting with the red cylinder, causing it to move.
3. **Sphere's Absence**: If the sphere were not present, the interaction between the red cylinder and the green sphere would be absent.
Now, let's consider the interactions without the sphere:
- The blue cylinder is moving towards the red cylinder.
- The red cylinder is moving towards the blue cylinder due to the influence of the green sphere.
- Without the sphere, the red cylinder would continue its path towards the blue cylinder.
Given this, the most likely interaction would be between the red cylinder and the blue cylinder, as they are both
moving towards each other and there are no other objects to interfere.
So, the most probable outcome is that the red cylinder and the blue cylinder will collide.
๐ค Uncertain Analysis:
Let's verify the options:
A. The cube collides with the blue cylinder - This is unlikely because the cube is not moving towards the blue cylinder.
B. The red object collides with the cube - This is also unlikely because the cube is not moving towards the red cylinder.
C. The red cylinder and the blue object collide - This is the most likely outcome based on their current paths.
Therefore, the correct answer is C.
๐จ Final Answer: <answer>C</answer> (correct)
๐ TW-GRPO (Ours) โ
๐ฏ Clear Observation:
The scene shows one blue cylinder, one teal cube, one green sphere, and one red cylinder on a flat
surface. Initially, there is no direct interaction between the objects as they are spread out.
However, upon closer observation, the red cylinder appears to be positioned near the teal cubes,
suggesting that it could potentially collide with them or another object if the sphere were
removed. The blue cylinders seem to be moving independently of each other and do not appear to have
any immediate interaction with the cubes unless they move into their paths.
๐ง Logical Deduction:
The person starts by placing three identical objects on the table, then moves
one aside and places another object behind them. This suggests that they are playing
a game where the hidden object is placed under one of the objects. Since the person
moved the first object aside and then placed something behind the remaining two,
it implies that the hidden object could be under either the second or the third
object from the left.
โ Confident Conclusion:
However, since the person's action of moving the first object aside indicates
that they might have intended for the hidden object to be under the second
object, it seems logical that the hidden object would be under the second
object from the left.
โ
Final Answer: <answer>A</answer> (correct)
๐ Key Advantages of TW-GRPO
| ๐ฏ Strength | ๐ Description |
|---|---|
| ๐ง Focused Data Extraction | Identifies and uses relevant information from videos |
| ๐ Logical Consistency | Maintains coherent reasoning from start to finish |
| โก Efficient Processing | Avoids redundant loops and contradictory statements |
| ๐ฏ Grounded Reasoning | Bases conclusions on observed evidence rather than assumptions |
๐ Conclusion
TW-GRPO demonstrates superior video reasoning capabilities across diverse tasks, achieving perfect accuracy through focused thinking and consistent logical chains. The token-level importance weighting enables more precise information extraction and reasoning, leading to significantly better performance compared to baseline methods.