Biology IA Exemplar: ¿Cómo afecta la exposición durante dos minutos… | RevisionDojo

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IB Biology SL Internal Assessment Example

¿Cómo afecta la exposición durante dos minutos a música rock y electrónica en la frecuencia cardíaca promedio (bpm) de estudiantes del primer año del Bachillerato Internacional de la Unidad Educativa JLM “La Salle”, en comparación con su frecuencia cardíaca basal en reposo?SL

Official IB Result

17/24

Criteria A: Research Design

5/6

Criteria StrandsPro

A.1Research question context

Excellent

A.2Methodological considerations

Good

A.3Methodology description

Poor

Criteria Feedback

The student frames the investigation in a specific and measurable biological context with a clear dependent variable and participant group.
The student chooses a repeated-measures structure that is well suited to controlling individual differences in heart rate.
The student explains several relevant controls, such as rest periods, headphones, environment, and prior activity.

The exact music tracks and their acoustic properties are not specified, which weakens the precision of the context.
Some important procedural details are missing, such as calibration of the volume setting and fuller recruitment information.
The documentation is not fully aligned across sections, creating avoidable confusion about the procedure and equipment.

1.1·Strength

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The research question is strong because it is specific, measurable, and clearly contextualized: the exposure time, participant group, musical conditions, and dependent variable are all defined. This gives the investigation a feasible scope and makes the intended comparison easy to follow.

1.2·Suggestion

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The student would strengthen the context by distinguishing the two genres more precisely. Rock and EDM are treated as if each were acoustically uniform, but track tempo, intensity, and instrumentation could differ within a genre. Naming the exact songs or describing their acoustic properties would make the design more scientifically grounded.

1.3·Weakness

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This method statement is too vague to be fully reproducible. The student should specify what the rest period actually was, how the volume setting of “70” was calibrated, and what other controls were applied consistently. Without those details, another investigator could not reliably repeat the procedure.

1.4·Strength

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The repeated-measures design is well chosen because each participant serves as their own control, which is appropriate for a heart-rate investigation with substantial individual variation. This reduces between-subject noise and matches the research question well.

1.5·Weakness

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The control is sensible in principle, but the explanation is still incomplete because it does not say how duration would distort the comparison or why 2 minutes was the best choice. The student should explain the methodological trade-off between a short exposure and the chance of missing a stable heart-rate response.

1.6·Suggestion

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A stronger methodology section would state how these 22 students were selected. If the sample was voluntary, convenience-based, or limited by class availability, that should be named explicitly so the reader can judge how representative the sample is.

1.7·Weakness

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The consent form conflicts with the actual investigation, which uses two genres rather than three and measures the heart rate with a pulsometer rather than a pulsioxímetro. This inconsistency weakens procedural credibility and suggests that the documentation was not fully aligned across the report.

Criteria B: Data Analysis

4/6

Criteria StrandsPro

B.1Communication of data recording and processing

Good

B.2Consideration of uncertainties

Moderate

B.3Data processing quality

Good

Criteria Feedback

The student presents the data in a generally clear way through raw-data tables, summary statistics, graphs, and test results.
The student chooses an appropriate paired-samples approach for repeated measures.
The student includes standard deviations, p-values, degrees of freedom, and sample size, which helps the reader follow the main comparisons.

The error bars are not defined, so the visual presentation of variation is ambiguous.
The processing does not show enough detail for all calculations to be independently followed.
The student does not directly compare the two music effects, so the analysis stops short of testing the key genre-to-genre claim.

2.1·Strength

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The data-processing plan is communicated clearly: the student identifies the descriptive statistics used and correctly selects a paired t-test for repeated measures. This helps the reader understand the logic of the analysis before the numerical results appear.

2.2·Strength

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The descriptive table is useful because it reports means, standard deviations, and sample size for each condition. That level of detail makes the summary statistics easy to interpret and compare across baseline and exposure conditions.

2.3·Weakness

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The student notes variability, but the uncertainty treatment is incomplete because the graph never defines what the error bars represent. The report should state whether they show standard deviation, standard error, or confidence intervals; otherwise the visual evidence is ambiguous.

2.4·Weakness

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The paired t-test is appropriate, but the processing stops short of the comparison needed to support a direct claim that electronic music had a larger effect than rock. The student should compare the change scores themselves rather than infer a stronger effect only from the smaller

p

-value.

2.5·Suggestion

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It would be helpful to add a brief note explaining the graph’s error bars and, if possible, to show the mean change scores more directly. That would make the visual processing easier to interpret and reduce ambiguity about the size of the two effects.

2.6·Question

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What would the student conclude if both tests were significant but the sequence were reversed or counterbalanced? Reflecting on that question would help distinguish statistical significance from a genuine comparison between the two music genres.

2.7·Weakness

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This is a relevant uncertainty, but it is not integrated into the analysis. The student should show how a

\pm 1

bpm reading resolution affects the smallest individual differences and whether those changes are meaningful relative to the reported averages and t-test results.

2.8·Suggestion

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The analysis would be stronger if the student distinguished measurement uncertainty from biological variability throughout the processing section, not only in the evaluation. Making that distinction earlier would improve precision and help the reader interpret the error bars and standard deviations correctly.

2.9·Weakness

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The appendix shows the raw paired differences, but the table is not leveraged in the main analysis to compare rock and electronic response directly. The student should use these difference scores to test whether the genre effects differ, rather than relying only on separate baseline-versus-condition tests.

Criteria C: Conclusion

4/6

Criteria StrandsPro

C.1Conclusion relevance and consistency

Good

C.2Scientific context comparison

Good

Criteria Feedback

The student answers the central question directly by linking both music conditions to increased heart rate relative to baseline.
The student connects the findings to broader physiological ideas such as autonomic regulation and prior research on music tempo and cardiovascular response.
The student's conclusion is biologically plausible and generally consistent with the numerical results they reported.

The student goes beyond what the analysis directly shows when they claim that one genre produced a more intense response than the other.
The comparison with scientific context is helpful, but it is not fully secured by the specific tracks and tempo information used in this investigation.
The conclusion would be stronger if it stayed closer to the exact comparisons actually tested.

3.1·Suggestion

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The conclusion would be stronger if the student briefly explained how the age and sex composition of the sample affects how confidently the results can be generalized. Linking the context back to the known physiology of adolescents would make the scientific comparison more balanced.

3.2·Strength

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The student usefully connects the findings to accepted physiological context, linking the heart-rate increase to autonomic modulation and prior literature. That comparison helps show why the results are biologically plausible rather than isolated numbers.

3.3·Weakness

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The scientific comparison here is plausible but not fully justified by the investigation because the actual tracks, tempo, and intensity values were not reported. The student should be careful not to infer a genre-wide mechanism from data that do not isolate those specific acoustic variables.

3.4·Strength

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The conclusion is clearly tied to the research question and is supported by the paired-test results showing an increase from baseline under both music conditions. This is a solid, relevant final answer to the core physiological question.

3.5·Weakness

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This overstates what the analysis shows. The report does not include a direct statistical comparison between the two change scores, so the claim that electronic music was definitively more intense than rock is not fully justified. The student should restrict the conclusion to what the analysis actually tested or add a direct comparison.

Criteria D: Evaluation

4/6

Criteria StrandsPro

D.1Methodological weaknesses

Good

D.2Improvements

Good

Criteria Feedback

The student identifies several specific limitations rather than relying on generic comments.
The student recognizes the importance of the fixed order of exposure and explains why it could bias the comparison.
The student proposes practical improvements such as counterbalancing, standardizing sound level, and using a more precise measuring device.

The relative importance of the weaknesses is not clearly prioritized.
Some limitations are described in a general way without being fully tied to the exact design choices in the student's investigation.
The student does not fully address the need to standardize and report the specific tracks and tempos used.

4.1·Strength

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The evaluation correctly identifies a concrete measurement limitation and connects it to the smallest observed changes. This is better than a generic statement because it shows the student understands why the device resolution matters for interpretation.

4.2·Strength

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This is a strong limitation because the student identifies a specific order effect and explains its likely direction. That shows a real understanding of how repeated-measures design can bias the comparison between genres.

4.3·Weakness

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This limitation is too generic and should be tied more explicitly to the actual investigation. The student claims a tempo effect, but the report does not measure or report tempo for the specific tracks used, so the critique should focus on that missing variable rather than on the genre label alone.

4.4·Weakness

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The improvement is realistic, but it is not fully tied to the specific weakness of the current investigation. The student should explain why ECG would be better than the pulsometer in terms of precision and whether the sound-isolated site is meant to control distraction, acoustic leakage, or both.

4.5·Suggestion

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This is a sensible extension, but it should be linked more explicitly to the limitation it addresses. Explaining whether HRV or blood pressure would help separate sympathetic activation from simple heart-rate fluctuation would make the improvement more methodologically meaningful.

4.6·Suggestion

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This is a strong improvement because it directly addresses the biggest design weakness and explains how each fix would improve validity. The student should add a similar suggestion for standardising and reporting the exact music tracks and tempos, since that is another major source of confounding.

4.7·Question

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If the sample were larger but the same fixed order and uncontrolled music tracks remained, how much would the overall validity really improve? Thinking about that helps prioritise which weaknesses most strongly affect the conclusion.

Loading scores...

Official IB Result

17/24

Criteria A: Research Design

5/6

Criteria StrandsPro

A.1Research question context

Excellent

A.2Methodological considerations

Good

A.3Methodology description

Poor

Criteria Feedback

The student frames the investigation in a specific and measurable biological context with a clear dependent variable and participant group.
The student chooses a repeated-measures structure that is well suited to controlling individual differences in heart rate.
The student explains several relevant controls, such as rest periods, headphones, environment, and prior activity.

The exact music tracks and their acoustic properties are not specified, which weakens the precision of the context.
Some important procedural details are missing, such as calibration of the volume setting and fuller recruitment information.
The documentation is not fully aligned across sections, creating avoidable confusion about the procedure and equipment.

1.1·Strength

Page 4• Click to view

1.2·Suggestion

Page 4• Click to view

1.3·Weakness

Page 5• Click to view

1.4·Strength

Page 5• Click to view

1.5·Weakness

Page 7• Click to view

1.6·Suggestion

Page 8• Click to view

1.7·Weakness

Page 21• Click to view

Criteria B: Data Analysis

4/6

Criteria StrandsPro

B.1Communication of data recording and processing

Good

B.2Consideration of uncertainties

Moderate

B.3Data processing quality

Good

Criteria Feedback

The student presents the data in a generally clear way through raw-data tables, summary statistics, graphs, and test results.
The student chooses an appropriate paired-samples approach for repeated measures.
The student includes standard deviations, p-values, degrees of freedom, and sample size, which helps the reader follow the main comparisons.

The error bars are not defined, so the visual presentation of variation is ambiguous.
The processing does not show enough detail for all calculations to be independently followed.
The student does not directly compare the two music effects, so the analysis stops short of testing the key genre-to-genre claim.

2.1·Strength

Page 9• Click to view

2.2·Strength

Page 9• Click to view

2.3·Weakness

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2.4·Weakness

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p

-value.

2.5·Suggestion

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2.6·Question

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2.7·Weakness

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This is a relevant uncertainty, but it is not integrated into the analysis. The student should show how a

\pm 1

bpm reading resolution affects the smallest individual differences and whether those changes are meaningful relative to the reported averages and t-test results.

2.8·Suggestion

Page 16• Click to view

2.9·Weakness

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Criteria C: Conclusion

4/6

Criteria StrandsPro

C.1Conclusion relevance and consistency

Good

C.2Scientific context comparison

Good

Criteria Feedback

The student answers the central question directly by linking both music conditions to increased heart rate relative to baseline.
The student connects the findings to broader physiological ideas such as autonomic regulation and prior research on music tempo and cardiovascular response.
The student's conclusion is biologically plausible and generally consistent with the numerical results they reported.

The student goes beyond what the analysis directly shows when they claim that one genre produced a more intense response than the other.
The comparison with scientific context is helpful, but it is not fully secured by the specific tracks and tempo information used in this investigation.
The conclusion would be stronger if it stayed closer to the exact comparisons actually tested.

3.1·Suggestion

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3.2·Strength

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3.3·Weakness

Page 13• Click to view

3.4·Strength

Page 13• Click to view

3.5·Weakness

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Criteria D: Evaluation

4/6

Criteria StrandsPro

D.1Methodological weaknesses

Good

D.2Improvements

Good

Criteria Feedback

The student identifies several specific limitations rather than relying on generic comments.
The student recognizes the importance of the fixed order of exposure and explains why it could bias the comparison.
The student proposes practical improvements such as counterbalancing, standardizing sound level, and using a more precise measuring device.

The relative importance of the weaknesses is not clearly prioritized.
Some limitations are described in a general way without being fully tied to the exact design choices in the student's investigation.
The student does not fully address the need to standardize and report the specific tracks and tempos used.

4.1·Strength

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4.2·Strength

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4.3·Weakness

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4.4·Weakness

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4.5·Suggestion

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4.6·Suggestion

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4.7·Question

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