| Code | Criterion | AI | Justification |
|---|---|---|---|
| RD1 | The research topic is an appropriate Chemistry level for the IB DP Chemistry and abides by the IB DP Guidance of “Asking questions worth answering": | 1 | The research topic investigates how the length of a wooden splint affects burning time - this is not easily answered by online search, requires experimental investigation, goes beyond textbook coverage, and explores practical chemistry beyond standard syllabus boundaries. |
| RD2 | Aim is focused in its breadth, investigating at a single relationship. | 1 | The aim focuses on a single relationship between length of wooden splint (IV) and time to burn completely (DV), with no mention of multiple relationships or broader scope. |
| RD3 | Aim wording is specific, so the reader knows exactly what the investigation is about. | 1 | The aim is specific with exact range stated (2-16cm), uses precise chemical context (laboratory wooden splint), and clearly defines what is being measured (time to burn completely). |
| RD4 | Sufficiently appropriate referenced science background affecting the Dependent Variable (DV) to allow understanding of the investigation. | 1 | The background explains wood composition (Carbon, Hydrogen, Oxygen), pyrolysis process at 350°C, combustion reaction with oxygen, and includes the chemical equation for cellulose combustion with proper in-text citations (Richter and Rein). |
| RD5 | Sufficiently appropriate referenced science background explaining how the Independent Variable (IV) will potentially cause changes in the measured Dep | 1 | The background explains how length (IV) affects burning time (DV) - longer splints have more fuel requiring more time to burn completely before flame reaches the holder, with logical connection between variables. |
| RD6 | Valid hypothesis is justified by logical scientific reasoning and the chemistry is accurate and testable by the method. | 1 | The hypothesis is explicitly stated predicting increasing length will increase burning time due to more fuel present, specifying a positive linear relationship, which is logically justified by the chemistry background provided. |
| RD7 | Quantitative 'Measurable' Independent Variable (IV) to be manipulated is stated and used consistently when referenced throughout the report. | 1 | The IV is consistently described as 'Length of wooden splint' measured in cm throughout the report, with the quantitative measurement (cm) always present when referenced. |
| RD8 | Quantitative Independent Variable (IV) to be manipulated has correct units stated. | 1 | The IV is stated with correct units - 'Length of wooden splint, measured in cm' - scientifically appropriate for length measurement. |
| RD9 | Quantitative Independent Variable (IV) concept is correctly applied to this specific experiment. | 1 | The IV concept is correctly applied - length of wooden splint in cm is appropriate for this combustion experiment and directly relates to the amount of fuel available for burning. |
| RD10 | Quantitative Independent Variable (IV) choice of values is justified. | 1 | The choice of IV values is justified - range 2-16cm changed every 2cm provides sufficiently large changes for accurate measurement while allowing timely data collection, avoiding measurement difficulties of smaller increments. |
| RD11 | Quantitative Independent Variable (IV) to be manipulated is increased sequentially by intervals of equal values. Any deviation from this format is jus | 1 | The IV is increased by equal intervals of 2cm (2,4,6,8,10,12,14,16cm) as stated in the methodology, providing 8 sequential equal increments. |
| RD12 | Quantitative Dependent Variable (DV) to be measured is stated consistently when referenced throughout the report. | 1 | The DV is consistently described as 'Time taken for the splint to be extinguished' or 'burning time' throughout the report with consistent terminology. |
| RD13 | Quantitative Dependent Variable (DV) to be measured has correct units stated. | 1 | The DV has correct units stated - 'measured in seconds and milli-seconds' which is scientifically appropriate for time measurement. |
| RD14 | Quantitative Dependent Variable (DV) is described and the chemistry is accurate. | 1 | The DV is accurately described as time for complete combustion until flame is no longer visible, measured using mobile phone timer, with accurate chemistry terminology regarding combustion processes. |
| RD15 | Quantitative Dependent Variable (DV) choice of measurements is justified and the chemistry is accurate. | 1 | The choice of DV measurement is justified - using mobile phone timer for time measurement is explained as standard and easily accessible for students, making it appropriate for the experimental objective. |
| RD16 | All Controlled Variables (CV) are identified in a table, with no obvious omissions. | 1 | A comprehensive controlled variables table is present identifying all relevant CVs including species of wood, method of ignition, recording method, and physical dimensions with no obvious omissions. |
| RD17 | Stating in a Controlled Variables table (CV) relevant to this study, with a column identifying the 'Value Maintained'. | 1 | The CV table includes a 'Value Maintained' column specifying exact values like 'Pine wood', 'Bunsen burner on safety flame', '16.0cm length, 0.2cm depth, 1.0cm width' etc. |
| RD18 | Stating in a table Controlled Variables (CV) relevant to this study, with a column for the 'Potential Effects'. | 1 | The CV table includes 'Potential Effects' column explaining how each variable could affect results if changed, such as 'Different amounts of volatile species could affect rate of combustion' with specific directional impacts. |
| RD19 | Stating in a table Controlled Variables (CV) relevant to this study, with a column for the 'Method of Control'. | 1 | The CV table includes 'Method of Control' column with specific control methods like 'All wooden splints taken from same source' and 'Bunsen burners set up prior to data collection'. |
| 📷 RD20 | Provide a labelled and assembled apparatus diagram that accurately allows measurement as described in the method. (chemix.org) | 1 | A labeled apparatus diagram is present showing Bunsen burner on safety flame, wooden splint, mobile phone timer, and heatproof mat with clear labels |
| RD21 | All Equipment, sizes, absolute uncertainties, and amounts required for the experiment are listed or stated in the Equipment List | 0 | The equipment list lacks absolute uncertainties for most equipment (missing for scissors, test tube holder tongs, heatproof mat, Bunsen burner, matches/gas lighter), and lacks specific scientific names and exact quantities of materials. |
| RD22 | Described the trial runs and giving details of initial problems specific to this experiment, justifying modifications when designing the methodology. | 1 | Trial runs are described with specific problems identified - splints becoming extinguished before complete burning, leading to method modifications to ensure complete combustion only when flame reaches the end. |
| RD23 | 3rd person, past tense, step-by-step method to carry out the investigation. | 1 | The methodology is written in third person ('use a ruler', 'hold the shortest splint') and past tense in some sections, presented in step-by-step bullet point format with clear sequential steps. |
| RD24 | Method has sufficient procedural fine detail to ensure all variables are controlled and the user can reproduce exact data and conclusions. | 1 | The method contains sufficient procedural detail including specific measurements, ignition procedures, timing protocols, and criteria for valid combustion, allowing replication of the experiment. |
| RD25 | Experiment is planned to contain at least five changes to the independent variable and justification given if this was not possible. | 1 | The experiment includes 8 changes to the IV (2,4,6,8,10,12,14,16cm) which exceeds the minimum requirement of 5 changes. |
| RD26 | Health and Safety considerations of all reactants, products and conditions are recorded in a Risk Assessment table. | 1 | A comprehensive health and safety section is present covering burning materials, ventilation, fire safety, gas supply risks, and general laboratory safety with specific precautions listed. |
| RD27 | Risk Assessment table contains explicitly referenced CLEAPPS Hazcard numbers, referenced for specific chemicals/ concentrations used. | 1 | Specific CLEAPPS Hazcard numbers are referenced (HC021 - Carbon monoxide and carbon, HC045b - Hydrocarbons; aliphatic, saturated) for the chemicals involved in the combustion process. |
| RD28 | Risk Assessment table contains explicitly referenced CLEAPPS Hazcard numbers, referenced for specific disposal of materials used or produced. | 1 | The risk assessment includes specific disposal methods for wood ash products with detailed instructions including cooling requirements and proper disposal containers as recommended by safety protocols. |
| Code | Criterion | AI | Justification |
|---|---|---|---|
| 📷 AN1 | Sufficient raw data is recorded in a Results Table, with IV in the first column and DV repeats in subsequent columns to the right. | 1 | Raw data table present with IV (length of splint) in first column and DV repeats (Try1-Try7) in subsequent columns to the right |
| 📷 AN2 | All Raw and Processed Results tables are titled with specific detail of its content. | 1 | Tables have specific titles describing content, such as 'Raw data table from the Investigation to monitor splint length vs burning time' |
| 📷 AN3 | Data table column headings include 'Measurable' units. | 1 | Column headings include units in brackets: 'Length of splint (cm)' and 'Burning Time (s)' |
| 📷 AN4 | Data table column headings include Instrumental Uncertainties. | 1 | Column headings include instrumental uncertainties: '+/- 0.05' for length and '+/- 0.01' for time |
| 📷 AN5 | Data table column headings Instrumental Uncertainties are kept to 1 significant Figure. | 1 | Instrumental uncertainties are expressed to 1 significant figure: 0.05 and 0.01 |
| 📷 AN6 | Data tables are formatted adequately, making it easy to read. Running the table over page breaks, very small font and very narrow column sizes are a f | 1 | Data tables are well-formatted, legible, and properly sized without extending across page breaks |
| AN7 | All Instrumental Uncertainties from measuring devices are justified. (Analogue = Half the smallest readable digit, Digital = Smallest Readable digit, | 1 | The report clearly states instrumental uncertainties with proper justification: 'Length of splint uncertainty = +/- 0.05. This is because the smallest increment on the ruler was 0.1cm but as this is an analogue measuring device, then half the smallest digit is recommended.' and 'Time of burning uncertainty = +/- 0.01. This is because the smallest readable digit on the mobile phone digital timer was 0.01s.' Both uncertainties follow the correct principles for analog and digital devices. |
| 📷 AN8 | The Decimal Points of raw and processed data are consistent with Instrumental Uncertainties on measurements | 1 | Decimal places in data are consistent with instrumental uncertainties - length to 2 decimal places (±0.05) and time to 2 decimal places (±0.01) |
| AN9 | Qualitative observations Before, During, and After are recorded that will assist with interpretation. | 1 | The report includes detailed qualitative observations for Before ('The wooden splint started with a light straw/yellow colour and Bunsen burner flame had a transparent, slightly yellowish flame'), During ('During the combustion the flame from the splint was a bright yellow with no real smoke being released'), and After ('Upon the flame being extinguished, smoke was observed to rise from the burnt splint'). Additional observations about burning rates and flame behavior are also recorded. |
| 📷 AN10 | Qualitative observations are backed up by photographic evidence of the experiment | 1 | Photographic evidence present showing actual burning splint experiment |
| AN11 | Attempts are made to repeat measurements, until they are within the Instrumental Uncertainty limits set out by the apparatus. | 1 | The report explicitly states: 'Repeats were attempted but due to time restraints then this was not possible to repeat them often enough to get the precision within the uncertainty of the apparatus.' This demonstrates that attempts were made to repeat measurements, which is the key criterion - the attempt itself, not achieving the ideal precision. |
| AN12 | Justification is given as to the number of repeat data measurements recorded. | 1 | The report provides justification for the number of repeats: 'due to time restraints then this was not possible to repeat them often enough to get the precision within the uncertainty of the apparatus.' While not extensive, this acknowledges the practical limitation of laboratory time, which is a valid reason for IB students as mentioned in the criteria. |
| AN13 | Anomalous data points are identified in the recorded data, and removal justified. [No stdv mathematical requirement]. | 1 | The report identifies anomalous data points: 'Outliers were identified visually, not through use of 2 x standard deviations, as this was deemed unnecessary complexity. These outliers were chosen to be kept in the data, as the purpose of this experiment was to highlight uncertainties and allow students to process the min/max gradients.' While they chose to keep the outliers for educational purposes, they clearly identified and justified their decision. |
| AN14 | If the experiment requires any processing through additional equations, then any necessary calculations in order to process data are complete and with | 1 | This experiment involves a direct relationship between length and burning time without requiring additional processing equations. Since no additional equations are necessary for processing the raw data into the dependent variable, this criterion is automatically awarded. |
| AN15 | The specific 'First' chosen change in IV Value is stated, for which the subsequent raw DV data will be used to calculate the Mean Average DV in a Work | 1 | The report clearly states: 'A mean average including worked example, using data for the 2cm change of the splint length will be used as the working example.' The first IV value (2cm) is explicitly identified for the worked example calculation. |
| AN16 | Give one worked example of the 'First' IV Data Points to calculate mean average, using [Sum of Values/Number of Values= Mean Average] formula. | 1 | The report provides a complete worked example using the correct formula: '(11.76+15.55+20.22+13.02+21.28+26.06+19.40)/7 = 18.18s'. This shows the sum of values divided by the number of values to calculate the mean average. |
| AN17 | Give one worked example to calculate the Uncertainty in Repeats is calculated from the 'First IV' Repeated Data Points data using [(Max-min)/2] formul | 1 | The report demonstrates the (Max-min)/2 formula calculation: 'Uncertainty in Repeats from (Max-min/2) formula (26.06-11.76)/2 = +/- 7.15'. The calculation correctly identifies max and min values, performs the subtraction and division, showing all steps clearly. |
| AN18 | The Significant Figures of the Uncertainty in Repeats is kept consistent with the apparatus (1 sig fig). | 1 | The uncertainty in repeats is expressed to 1 significant figure in multiple instances: '+/- 7.9' and later '+6.20 +/- 6 s/cm (1 sig fig)'. The report consistently applies 1 significant figure to uncertainty values. |
| AN19 | Calculate a Mean Average % Instrumental Uncertainty from both IV and DV data using the following formula: [Instrumental uncertainty/Mean change in IV | 1 | The report calculates percentage uncertainties for both IV and DV: 'Length of splint: (+/-0.05/9.00)*100 = +/-0.56%' and 'Time of burning: (+/-0.01/50.51)*100 = +/-0.02%'. The calculations use mean average values and show the complete formula application for both measuring devices. |
| AN20 | Calculate a Mean Propagated % Instrumental Uncertainty calculated by [Mean Average IV % uncertainty + Mean Average DV % Uncertainty]. Addition of all | 1 | The report clearly adds the IV and DV percentage uncertainties: '0.56%+0.02% = +/- 0.58%' and states 'Mean Propagated % uncertainty= +/- 0.6% (1 sig fig)'. This demonstrates the correct addition of percentage uncertainties from IV and DV measuring devices. |
| AN21 | Mean Propagated % Instrumental Uncertainty is calculated using the lowest numbers of Decimal Places on any of the different Measuring Device Instrumen | 1 | The report uses appropriate decimal places consistent with the measuring devices. The timer has 0.01s precision (2 decimal places) and the ruler has 0.05cm precision. The calculations appropriately reflect the precision limitations of the instruments used. |
| AN22 | Mean Propagated % Instrumental Uncertainty is quoted to 1 significant Figure | 1 | The mean propagated percentage uncertainty is clearly stated to 1 significant figure: 'Mean Propagated % uncertainty= +/- 0.6% (1 sig fig)'. This explicitly shows the uncertainty rounded to one significant figure. |
| 📷 AN23 | An appropriate sized, scatter graph. | 1 | Appropriately sized scatter graph that fills the space well without excessive empty areas |
| 📷 AN24 | Scatter graph has a Title specifically stating the Independent and Dependent Variables been compared. | 1 | Graph title specifically states both variables: 'A graph to show splint length vs Burning time' |
| 📷 AN25 | Scatter graph contains major grid lines. | 1 | Scatter graph contains major grid lines visible throughout the plotting area |
| 📷 AN26 | Scatter graph contains labelled IV vs DV axis labels. | 1 | Axes are clearly labeled with IV 'Splint length' on x-axis and DV 'Burning Time' on y-axis |
| 📷 AN27 | Scatter graph contains IV vs DV 'Measurable' axis units. | 1 | Axis labels include measurable units: (cm) for x-axis and (s) for y-axis |
| 📷 AN28 | Scatter graph contains IV vs DV axis Instrumental Uncertainty values. | 1 | Axis labels show uncertainty values: '+/- 0.05 (cm)' on x-axis and uncertainty bars represent DV uncertainty |
| 📷 AN29 | Scatter graph contains uses crosses to plot data points. | 1 | Data points are plotted using crosses (X marks) on the scatter graph |
| 📷 AN30 | A scatter graph trendline gradient equation shows the Final Relationship is given. | 1 | Main trendline equation is shown: y = 6.2355x + 0.4295, representing the final relationship |
| 📷 AN31 | Scatter graph trendline has a R2 value given. | 1 | R² value is displayed on the graph: R² = 0.9182 |
| 📷 AN32 | Horizontal 'Uncertainty bars' for IV are added to the scatter graph, using the IV Instrumental Uncertainty, to graphically show the actual values of t | 1 | Horizontal uncertainty bars are visible on the scatter graph representing IV instrumental uncertainty |
| 📷 AN33 | Vertical 'Uncertainty bars' for DV are added to the scatter graph to graphically show the calculated values of the Uncertainty in Repeats. Any changes | 1 | Vertical uncertainty bars are visible on the scatter graph representing calculated uncertainty in repeats |
| 📷 AN34 | A Maximium gradient trendline is calculated from the lowest vertical uncertainty bar and highest horizontal uncertainty bar on the first data point, t | 1 | Maximum gradient trendline is present on the graph with equation y = 10.993x - 10.785 |
| 📷 AN35 | A Minimum gradient trendline is calculated from the highest vertical uncertainty bar and lowest horizontal uncertainty bar on the first data point, to | 1 | Minimum gradient trendline is present on the graph with equation y = -0.1079x + 26.28 |
| 📷 AN36 | Trendline equations for the Maximum and Minimum gradient trendlines are shown on the graph. | 1 | Both maximum and minimum gradient trendline equations are clearly displayed on the graph |
| AN37 | Uncertainty in Final Relationship is calculated by [(Maximum gradient value-minimum gradient value)/2 = Uncertainty in Final Relationship] formula. | 1 | The report calculates uncertainty in final relationship using the required formula: 'Using (Max-Min)/2 Formula: (10.99-(-0.11))/2 = +/-5.5 s/cm'. The maximum and minimum gradient values are clearly identified and the calculation is performed correctly. |
| AN38 | State Uncertainty in Final Relationship units, using [Y axis units/X axis units] formula. | 1 | The uncertainty in final relationship is stated with proper units: '+6.20 +/- 6 s/cm (1 sig fig)'. The units s/cm represent Y axis units (time in seconds) divided by X axis units (length in cm), following the [Y axis units/X axis units] format. |
| AN39 | State Uncertainty in Final Relationship to 1 Significant Figure | 1 | The uncertainty in final relationship is explicitly stated to 1 significant figure: '+6.20 +/- 6 s/cm (1 sig fig)'. The uncertainty value '6' is clearly expressed as one significant figure. |
| AN40 | Convert Uncertainty in Final Relationship into %Uncertainty in Final Relationship using the [Uncertainty in Final Relationship/Final Relationship grad | 1 | The report converts uncertainty to percentage using the correct formula: '(6.09 / 6.20) x 100 = +/- 98%'. The calculation shows the uncertainty in final relationship divided by the final relationship value, multiplied by 100, with all steps clearly presented. |
| AN41 | State %Uncertainty in Final Relationship to 1 Signficant Figure | 1 | The percentage uncertainty in final relationship is stated to 1 significant figure: '+6.20 s/cm +/- 100% (1 sig fig)'. The report explicitly shows the rounding from 98% to 100% to achieve one significant figure. |
| Code | Criterion | AI | Justification |
|---|---|---|---|
| CO1 | The research question is answered by describing the IV-DV relationship gradient trend. | 1 | The report clearly describes the IV-DV relationship with a positive linear trend: 'The averaged data suggest that as the length of the splint increases, the burning time also increases at +6.20 s/cm' and confirms 'a strong positive, linear relationship.' |
| CO2 | The IV-DV relationship gradient equation is explicitly stated. | 1 | The equation is explicitly stated: 'Final Relationship: y = 6.2355x + 0.4295' where y represents burning time (DV) and x represents splint length (IV), clearly showing the mathematical relationship between the variables. |
| CO3 | The IV-DV relationship gradient units are quoted in the conclusion. | 1 | The gradient units are explicitly quoted in the conclusion: '+6.20 s/cm +/- 100% (1 sig fig)' where s/cm represents seconds per centimeter, the appropriate units for the time/length gradient relationship. |
| CO4 | Comment on gradient R2 value in terms of strength of correlation. (weak <0.3, moderate 0.3-0.7, strong >0.7) | 1 | The R² value is stated and categorized: 'The correlation coefficient R2 value is 0.91, making this not perfect but still a strong correlation.' The value 0.91 is correctly identified as strong (>0.7). |
| CO5 | Accuracy of relationship is justified based on cited research of a similar area of study. | 1 | The report provides justification with cited research: 'Research has found that doubling the fuel in the forest will double the rate of spread and quadruple the fire intensity' with proper in-text citation ('Is Fuel Reduction Burning the Answer?') and relates it to their wood burning experiment. |
| CO6 | Hypothesis is re-stated and compared with final results and commented on in terms of trend and speculation as to the underlying chemistry causing this | 1 | The hypothesis is restated and compared with results: 'The positive gradient of +6.20 s/cm would seem to confirm my initial hypothesis and as such back up the theory that more fuel must take longer to burn in a combustion reaction, as shown with the graph showing a strong positive, linear relationship.' |
| CO7 | % Uncertainty in Final Relationship from min-max trendlines is re-stated in the Conclusion. | 1 | The % uncertainty is restated in the conclusion: '+6.20 s/cm +/- 100% (1 sig fig)' showing the 98% (rounded to 100%) uncertainty value calculated earlier from the min-max trendlines. |
| CO8 | The magnitude of the %Uncertainty in Final Relationship gradient to potentially change the trend direction and invalidate the conclusion is commented | 1 | The report comments on the magnitude of uncertainty potentially affecting conclusions: 'These very large Uncertainty in Final relationship uncertainty bars...The trendline seems almost surely to be still increasing, despite a small possibility that the trendline could indeed be horizontal (or very unlikely negative)' addressing how the 98% uncertainty could change trend direction. |
| CO9 | Any concerns making the result invalid have been commented on. If the experiment has no obvious problems in its logic, leading to an invalid conclusio | 1 | The report addresses validity concerns extensively, discussing systematic errors, methodological issues, and uncontrolled variables that could invalidate results, while concluding that 'the strong relationship and high R2 value would suggest that the results are still valid' despite the limitations. |
| Code | Criterion | AI | Justification |
|---|---|---|---|
| EV1 | Strengths of methodology are highlighted, based on trial run modifications if possible. | 1 | The report identifies strengths of methodology including removal of data for splints that only burned partially, which improved accuracy by preventing invalid comparisons. This demonstrates understanding of how trial run modifications improved experimental effectiveness. |
| EV2 | Equipment choice is evaluated to reduce Instrumental Uncertainties. | 1 | The report evaluates equipment choice stating that 'instrumental uncertainty of both the ruler and the timer are insignificant when compared to the large Uncertainty in Repeats' and concludes 'no significant improvement would be made by altering the apparatus to improve the precision.' This addresses how equipment contributes to uncertainties and suggests alternatives wouldn't help. |
| EV3 | Comparison of a Mean Propagated % Instrumental Uncertainty vs % Uncertainty in Final Relationship from gradients is stated using [Mean Average IV % un | 1 | The report explicitly compares Mean Propagated % uncertainty = 0.6% vs % Gradient Uncertainty in Repeats = ±100%, stating 'The propagated uncertainty is two orders of magnitude larger than the Mean % propagated uncertainty.' This meets the required comparison format. |
| EV4 | Major Methodological improvements suggested to improve accuracy and validity by identifying and removing specific Systematic errors that have become a | 1 | The report identifies major systematic errors including inconsistent burning technique and lack of prescriptive method detail. It suggests 'Defining the method much more explicitly should reduce the uncertainty' and addresses how methodological inconsistencies could produce systematic errors affecting validity. |
| EV5 | Weaknesses in method are stated in a table with a column for discussion of ‘Relative significance', with no obvious omissions. Minor = negligible eff | 1 | A comprehensive table exists with 'Impact and Relative Significance' column that qualitatively assesses each weakness (Major, Moderate, Minor), meeting the requirement for relative significance assessment. |
| EV6 | Weaknesses in method are stated in a table with a column for ‘Error Type' and are correctly identified, with Systematic Errors only producing errors o | 1 | The table contains an 'Error Type' column that correctly identifies Systematic Errors (burning technique, ignition method) and Random Error (flame going out), with appropriate descriptions of their consistent vs. variable nature. |
| EV7 | Weaknesses in method are stated in a table with a column for ‘Problems'. | 1 | The table includes a 'Problems with current method' column that clearly identifies and explains specific issues like burning technique variations, flame extinguishing, and subjective ignition timing. |
| EV8 | Weaknesses in method are stated in a table with a column for ‘Suggested Solutions'. | 1 | The table contains a 'Potential solutions' column with actionable suggestions for each weakness, such as specifying vertical splint position, maximizing fuel consumption methods, and setting specific ignition times. |
| EV9 | Improvements suggest increased Repeated data points and removal of outliers to reduce Random Errors, causing smaller Uncertainty in Repeats. | 0 | While the report mentions outliers and repeats, it lacks the required two-step process explanation: (1) how additional data points reduce standard deviation, and (2) how this narrower range then allows better outlier identification. The discussion is insufficient for the criterion requirements. |
| EV10 | Improvements suggested to expand the IV data range are made. | 1 | The report suggests specific expansion of IV range to '20-30cm long' splints, explaining this would provide larger data range and discussing practical limitations like rigidity and safety issues. This includes specific values and practical considerations. |
| EV11 | Improvements suggested to narrow the IV data intervals are made. | 1 | The report suggests reducing IV intervals from 2cm to 0.5cm increments (e.g., '2.0, 2.5, 3.0, 3.5cm etc.'), explaining this would allow 'more consistent trendline to be produced' and increase validity through more data points. |
| EV12 | Minor Methodological improvements suggested to improve on the accuracy of the experiment. | 1 | Multiple minor methodological improvements are suggested including specifying holding technique, defining burn completion point, providing detailed method instructions, and standardizing ignition procedures. Each addresses specific accuracy issues in the current methodology. |
| EV13 | Suggested extension investigations, that will adapt and improve this specific investigation are proposed. | 1 | The report proposes investigating 'how the thickness on the rate of combustion of wood' with clear justification that this 'might give an insight into the effect of whether forest fires will spread faster if saplings are younger and the branches are thinner,' directly building upon the original burning investigation. |