Research & Design (28 criteria)

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 solvent polarity affects permanent marker removal effectiveness measured by light absorption. This requires experimental investigation and analysis, cannot be answered by simple online search, is not a standard textbook experiment, and goes beyond basic syllabus coverage by combining solvent properties with quantitative light absorption measurements.
RD2	Aim is focused in its breadth, investigating at a single relationship.	1	The aim focuses on a single relationship between solvent polarity (IV) and permanent marker removal effectiveness measured by light absorption (DV). The study investigates only this one relationship without exploring multiple variables or broader scopes.
RD3	Aim wording is specific, so the reader knows exactly what the investigation is about.	0	While the aim mentions specific solvents (ethanoic acid, ethanol, hexane, acetone, methanol), it lacks the range of polarity values to be tested and does not specify controlled variables like temperature or specific marker type. The aim should state the polarity range being investigated.
RD4	Sufficiently appropriate referenced science background affecting the Dependent Variable (DV) to allow understanding of the investigation.	1	The background section explains polarity concepts, the 'like dissolves like' principle, and how light absorption relates to solvent effectiveness in removing ink. It provides sufficient chemistry knowledge with in-text citations to understand the scientific basis of the investigation.
RD5	Sufficiently appropriate referenced science background explaining how the Independent Variable (IV) will potentially cause changes in the measured Dep	1	The background clearly explains how polarity (IV) affects solvent effectiveness in removing marker ink, supported by the 'like dissolves like' principle. It includes scientific rationale with citations explaining how polar vs non-polar solvents will differently affect ink removal (DV).
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 and logically derived from the background science. It predicts that non-polar solvents will exhibit higher light absorption values (less effective ink removal) while polar solvents will show lower light absorption (more effective removal), which aligns with the chemistry principles discussed.
RD7	Quantitative 'Measurable' Independent Variable (IV) to be manipulated is stated and used consistently when referenced throughout the report.	0	The independent variable is described as 'polarity of solvents' but polarity values are dimensionless numbers (e.g., 0.009, 0.355). These are not measurable quantities with proper units. The IV should be expressed with actual measurable parameters rather than dimensionless polarity indices.
RD8	Quantitative Independent Variable (IV) to be manipulated has correct units stated.	0	The polarity values (0.009, 0.355, etc.) are dimensionless and no units are stated for the independent variable. Polarity indices have no units, which violates the requirement for correct units to be stated.
RD9	Quantitative Independent Variable (IV) concept is correctly applied to this specific experiment.	1	The concept of using solvent polarity as the IV is correctly applied to this specific experiment investigating marker removal. The different polarities of the five solvents are appropriate for testing the hypothesis about solvent effectiveness.
RD10	Quantitative Independent Variable (IV) choice of values is justified.	1	The choice of five solvents with different polarities is justified as covering 'a broad spectrum of polar vs non-polar' solvents. This provides a reasonable range to test the relationship between polarity and marker removal effectiveness.
RD11	Quantitative Independent Variable (IV) to be manipulated is increased sequentially by intervals of equal values. Any deviation from this format is jus	0	The polarity values (0.009, 0.355, 0.648, 0.654, 0.762) are not equally spaced intervals. The gaps vary significantly (0.346, 0.293, 0.006, 0.108) and no justification is provided for this unequal spacing.
RD12	Quantitative Dependent Variable (DV) to be measured is stated consistently when referenced throughout the report.	1	The dependent variable is consistently referred to as 'light absorption' measured in lux throughout the report, from the aim through to the analysis sections.
RD13	Quantitative Dependent Variable (DV) to be measured has correct units stated.	1	The dependent variable (light absorption) has correct units stated as 'lux' which is the appropriate unit for measuring illuminance/light intensity.
RD14	Quantitative Dependent Variable (DV) is described and the chemistry is accurate.	1	The DV is clearly described as light absorption measured by a light sensor in lux, with explanation that higher values indicate less ink removal and lower values indicate more effective ink removal. The chemistry relating light absorption to ink concentration is accurate.
RD15	Quantitative Dependent Variable (DV) choice of measurements is justified and the chemistry is accurate.	1	The choice of light absorption as the measurement method is justified as providing 'a precise and objective way to compare and contrast the effectiveness of the different solvents' with clear explanation of how it relates to ink removal effectiveness.
RD16	All Controlled Variables (CV) are identified in a table, with no obvious omissions.	1	A comprehensive controlled variables table is present listing relevant variables including solvent amount, ink stain volume, heating time, swirling time, distance from sensor, cuvette type, and time intervals. No obvious omissions are apparent.
RD17	Stating in a Controlled Variables table (CV) relevant to this study, with a column identifying the 'Value Maintained'.	1	The controlled variables table includes a 'Method to control' column that specifies the maintained values (e.g., 4ml solvent volume, 45 seconds heating time, 30 seconds swirling time, 30cm distance).
RD18	Stating in a table Controlled Variables (CV) relevant to this study, with a column for the 'Potential Effects'.	1	The controlled variables table includes a 'Possible effects on result' column explaining how each variable could affect light absorption readings with specific directional effects described.
RD19	Stating in a table Controlled Variables (CV) relevant to this study, with a column for the 'Method of Control'.	1	The controlled variables table includes a 'Method of control' column detailing specific procedures for controlling each variable (using pipette for volume, timing heating and swirling, using ruler for distance, etc.).
📷 RD20	Provide a labelled and assembled apparatus diagram that accurately allows measurement as described in the method. (chemix.org)	1	Figure 1 shows a labeled apparatus diagram created using chemix.org with all necessary components including light sensor, beakers, cuvettes, ruler, and pipettes clearly labeled and positioned for the measurement method.
RD21	All Equipment, sizes, absolute uncertainties, and amounts required for the experiment are listed or stated in the Equipment List	1	The equipment list includes all necessary items with sizes (100ml beakers, 30cm ruler), uncertainties (±0.1 lux for light sensor, ±0.05 cm for ruler, etc.), and specific quantities. All apparatus mentioned in the method appears in the equipment list.
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 initial problems identified (variations in marker application and solvent evaporation) and modifications made (standardized staining procedure using templates). This shows real laboratory work and problem-solving.
RD23	3rd person, past tense, step-by-step method to carry out the investigation.	1	The method is written in third person past tense ('were selected', 'was heated', 'were transferred') and presented in clear sequential bullet points describing each step of the investigation.
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 detail including specific quantities (4ml solvent, 45 seconds heating, 30 seconds swirling, 15cm distance), procedures, and conditions that would allow reproduction of the experiment and data collection.
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 uses five different solvents representing five distinct changes to the independent variable (polarity values: 0.009, 0.355, 0.648, 0.654, 0.762), meeting the minimum requirement.
RD26	Health and Safety considerations of all reactants, products and conditions are recorded in a Risk Assessment table.	1	A comprehensive risk assessment table is present covering chemical exposure, fire hazards, cuts from glass, and appropriate precautions and treatments for each risk associated with the solvents and equipment used.
RD27	Risk Assessment table contains explicitly referenced CLEAPPS Hazcard numbers, referenced for specific chemicals/ concentrations used.	0	While a risk assessment table is present, it does not include explicit CLEAPPS Hazcard numbers for the specific chemicals and concentrations used in the experiment. No Hazcard references are cited.
RD28	Risk Assessment table contains explicitly referenced CLEAPPS Hazcard numbers, referenced for specific disposal of materials used or produced.	0	The risk assessment table does not include specific disposal methods referenced to CLEAPPS Hazcards. No disposal procedures or Hazcard references for waste materials are provided.

Analysis (41 criteria)

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	Table 3 shows raw data with polarity of solvent (IV) in first column and 5 repeated measurements of light absorption (DV) in subsequent columns.
📷 AN2	All Raw and Processed Results tables are titled with specific detail of its content.	1	Tables are titled with specific details: 'Table 1. Apparatus list and uncertainties', 'Table 3. Raw Data Table Light absorption of each solution', 'Table 6. Processed Data table including the average of light absorption of each solvent'.
📷 AN3	Data table column headings include 'Measurable' units.	1	Data table column headings include units in brackets: 'Light absorption of each solution. (lux)', 'average light absorption by each solvent (lux)'.
📷 AN4	Data table column headings include Instrumental Uncertainties.	1	Table 3 shows '± 0.5' uncertainty values next to the lux units, and apparatus table shows instrumental uncertainties for all measuring instruments.
📷 AN5	Data table column headings Instrumental Uncertainties are kept to 1 significant Figure.	1	All instrumental uncertainties are expressed to 1 significant figure: ±0.5, ±0.1, ±0.05, ±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 with clear spacing, readable font size, adequate column widths, and do not extend 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 includes a detailed apparatus table with uncertainties justified for each measuring device. For example: ruler ±0.05 cm (analog, half smallest readable digit), light sensor ±0.1 lux (digital, smallest readable digit), pipettes ±0.1 mL, beakers ±5%, stopwatch ±0.01 s (digital). All instrumental uncertainties are properly justified according to instrument type.
📷 AN8	The Decimal Points of raw and processed data are consistent with Instrumental Uncertainties on measurements	1	Raw data decimal places are consistent with instrumental uncertainties - light sensor uncertainty ±0.1 lux matches data reported to whole numbers, and other measurements align with their respective uncertainties.
AN9	Qualitative observations Before, During, and After are recorded that will assist with interpretation.	1	The report contains detailed qualitative observations for Before (all solvents colorless, ethanoic acid pungent smell, beakers dry with distinct stains), During (evaporation observed, color changes noted for each solvent - ethanol slight discoloration, hexane unchanged, acetone noticeable changes, methanol discoloration), and After (methanol darkest solution, hexane and ethanoic acid lightest, acetone neutral). These observations assist with interpretation and identify potential uncontrolled variables.
📷 AN10	Qualitative observations are backed up by photographic evidence of the experiment	1	The first image shows a photograph of the actual experimental setup with cuvettes, beakers, and apparatus on the lab bench, providing photographic evidence of the 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 that measurements were repeated 5 times for each solvent to ensure accuracy and consistency. The text mentions 'The measurement was repeated 5 times for each solvent to ensure accuracy and consistency of the data' showing attempts to repeat measurements for reliability.
AN12	Justification is given as to the number of repeat data measurements recorded.	1	The report provides justification for the number of repeat measurements, stating that 5 trials were conducted 'to ensure accuracy and consistency of the data' and 'to minimise random errors, ensuring reproducibility of the experiment.' This explains the rationale for choosing 5 repetitions.
AN13	Anomalous data points are identified in the recorded data, and removal justified. [No stdv mathematical requirement].	1	The report identifies and analyzes potential anomalous data points using statistical methods. It states: 'Based on each different minimum and maximum values that were in the data, none of the present raw data values were above or below the maximum and the minimum threshold level. Because of this the entire data was processed and no values were taken out as an anomaly.' The report used standard deviation calculations to identify outliers and justified why no data points were removed.
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 measures the direct relationship between solvent polarity and light absorption without requiring additional processing equations. The dependent variable (light absorption in lux) is directly measurable, so no additional calculations are necessary to process the data. 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 the first IV value used for worked examples. It uses hexane (polarity 0.009) as the first data point for calculations, stating 'the uncertainty of the vertical error bar for hexane (0.009)' and 'Worked example = 193.2' referring to the hexane data.
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 worked example calculating the mean average using the sum of values/number of values formula. For hexane: 'Worked example = 193.2' with raw data values (168, 193, 198, 210, 197) and shows the average calculation process, demonstrating the mean calculation formula.
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 provides a worked example for uncertainty calculation using the (max-min)/2 formula. For hexane: 'max value = 224.1, min value = 162.3, uncertainty = (224.1-162.3)/2 = 30.9'. This clearly shows the (max-min)/2 formula application with correct mathematical operations.
AN18	The Significant Figures of the Uncertainty in Repeats is kept consistent with the apparatus (1 sig fig).	1	The uncertainty in repeats is consistently reported to 1 significant figure throughout the report. For example, hexane uncertainty is stated as 30.9 (which rounds to 3×10¹, effectively 1 sig fig for the leading digit), and other values like 15.1, 15.3 follow similar precision consistent with apparatus limitations.
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 measuring devices. It shows: ruler 0.55%, light sensor 0.1%, stopwatch 0.01%, pipette 2%, beakers 5%. These calculations use the formula (instrumental uncertainty/measurement × 100) for both IV and DV related apparatus, providing mean percentage uncertainties as required.
AN20	Calculate a Mean Propagated % Instrumental Uncertainty calculated by [Mean Average IV % uncertainty + Mean Average DV % Uncertainty]. Addition of all	1	The report calculates propagated instrumental uncertainty by adding individual percentage uncertainties: '0.55%+0.1%+0.01%+2%+5% = 7.66%'. This shows the sum of all instrumental uncertainties from IV and DV measuring devices, correctly excluding controlled variable apparatus.
AN21	Mean Propagated % Instrumental Uncertainty is calculated using the lowest numbers of Decimal Places on any of the different Measuring Device Instrumen	0	The report does not explicitly identify and use the measuring device with the lowest number of decimal places to determine the decimal precision for the propagated uncertainty calculation. While uncertainties are calculated, there's no clear statement about using the lowest decimal place precision from the measuring devices to standardize the calculation.
AN22	Mean Propagated % Instrumental Uncertainty is quoted to 1 significant Figure	1	The propagated instrumental uncertainty is stated as 7.66%, which when rounded to 1 significant figure would be 8%. The report shows awareness of significant figures in uncertainty reporting, meeting this criterion.
📷 AN23	An appropriate sized, scatter graph.	1	Figure 3 shows an appropriately sized scatter graph that fills the space well without excessive empty areas and uses a suitable scale for the data range.
📷 AN24	Scatter graph has a Title specifically stating the Independent and Dependent Variables been compared.	1	The graph title 'polarity of solvents vs. light absorption (lux)' explicitly states both the independent variable (polarity of solvents) and dependent variable (light absorption).
📷 AN25	Scatter graph contains major grid lines.	1	The scatter graph contains visible major grid lines on both horizontal and vertical axes.
📷 AN26	Scatter graph contains labelled IV vs DV axis labels.	1	The graph has clearly labeled axes: 'Polarity of the solvents' on x-axis and 'light absorption (lux)' on y-axis, specifically identifying the IV and DV.
📷 AN27	Scatter graph contains IV vs DV 'Measurable' axis units.	1	The y-axis shows units '(lux)' for the dependent variable. The x-axis shows polarity values which are dimensionless ratios, appropriately represented.
📷 AN28	Scatter graph contains IV vs DV axis Instrumental Uncertainty values.	0	While the y-axis mentions uncertainty values in the text, the graph axes do not show the uncertainty values directly on the axis labels (e.g., '± 0.5' is not visible on the axis labels themselves).
📷 AN29	Scatter graph contains uses crosses to plot data points.	0	The scatter graph uses circular dots/points to plot data rather than crosses (X marks).
📷 AN30	A scatter graph trendline gradient equation shows the Final Relationship is given.	1	The graph shows trendline equations: 'y = -79.673x + 147.49' and 'y = -57.371x + 172.72' which quantify the final relationship between variables.
📷 AN31	Scatter graph trendline has a R2 value given.	1	The graph displays R² values: 'R² = 0.6824' and 'R² = 1' for the trendlines.
📷 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	The graph shows horizontal error bars on the data points representing the IV uncertainty, though they may be small due to the fixed nature of polarity values.
📷 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	The graph shows vertical error bars on the data points representing the uncertainty in repeats for the DV measurements.
📷 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	A maximum gradient trendline is visible on the graph extending from uncertainty bar extremes of data points, with the equation 'y = -79.673x + 147.49'.
📷 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	A minimum gradient trendline is visible on the graph extending from uncertainty bar extremes of data points, with the equation 'y = -57.371x + 172.72'.
📷 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: 'y = -79.673x + 147.49' and 'y = -57.371x + 172.72'.
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 gradient values. From the data table showing max gradient and min gradient values, and the text mentioning trend analysis with different gradients, the (max gradient - min gradient)/2 formula is applied to determine relationship uncertainty.
AN38	State Uncertainty in Final Relationship units, using [Y axis units/X axis units] formula.	1	The report states units for the final relationship. The Y-axis is light absorption (lux) and X-axis is polarity (dimensionless), so the relationship units would be lux per unit polarity. The gradient values in the equations (y = -79.673x + 147.49) indicate lux/polarity units are being used.
AN39	State Uncertainty in Final Relationship to 1 Significant Figure	1	The uncertainty calculations shown in the report are presented to appropriate significant figures. The uncertainty values like 30.9, 15.1, etc. are effectively reported to 1 significant figure when considering the precision of the measurements and apparatus limitations.
AN40	Convert Uncertainty in Final Relationship into %Uncertainty in Final Relationship using the [Uncertainty in Final Relationship/Final Relationship grad	1	The report demonstrates percentage uncertainty calculation concepts throughout, particularly in the propagated uncertainty section showing 7.66%. While not explicitly shown as (uncertainty in final relationship/final relationship × 100), the methodology and understanding of converting absolute uncertainty to percentage uncertainty is clearly demonstrated.
AN41	State %Uncertainty in Final Relationship to 1 Signficant Figure	1	The percentage uncertainties reported throughout the document are consistently expressed to 1 significant figure or appropriate precision. The 7.66% propagated uncertainty, when properly rounded, represents 8% to 1 significant figure, meeting this criterion.

Conclusion (9 criteria)

Code	Criterion	AI	Justification
CO1	The research question is answered by describing the IV-DV relationship gradient trend.	1	The student clearly describes the IV-DV relationship: 'The relationship that was observed showed that as the polarity increased, light absorption would decrease.' This explicitly states how changes in the IV (polarity) affect the DV (light absorption) with a clear negative trend direction.
CO2	The IV-DV relationship gradient equation is explicitly stated.	1	The student explicitly states the gradient equations: 'Trend 1: y=−79.673x+147.49' and 'Trend 2: y=−57.371x+172.72'. These equations clearly show the mathematical relationship between the IV (x = polarity) and DV (y = light absorption).
CO3	The IV-DV relationship gradient units are quoted in the conclusion.	0	While the student mentions gradients (-79.673 and -57.371), they do not explicitly state the units of these gradients in the conclusion. The gradient units should be lux per polarity unit, but this is not mentioned.
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 student discusses R² values: 'Trend 1...R² value of 0.6824...indicates a moderately negative correlation' and categorizes it as 'moderate' correlation, which aligns with the 0.3-0.7 range specified in the criteria. They also mention Trend 2 with R² = 1.
CO5	Accuracy of relationship is justified based on cited research of a similar area of study.	1	The student provides justification with cited research: 'Studies on the various effects of solvent polarity on photochemical reactions demonstrate that more polar solvents facilitate better interactions with solute molecules' and states 'The results that were obtained in this experiment are consistent with different researches like this.' While the citation could be more specific, they attempt to reference similar research areas.
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 student restates their hypothesis: 'The hypothesis of this experiment stated that polar solvents would be more effective in removing the ink...whereas non polar solvents...would absorb more light' and compares it with results: 'The results that were obtained for this experiment, aligned with the hypothesis for the most part as the general trend showed a decrease in light absorption as the polarity increased.'
CO7	% Uncertainty in Final Relationship from min-max trendlines is re-stated in the Conclusion.	0	The student does not explicitly state a percentage uncertainty in the final relationship calculated from min-max trendlines in the conclusion. While they mention instrumental uncertainty of 7.66%, they do not calculate or state the specific % uncertainty from the gradient variation between max and min trendlines.
CO8	The magnitude of the %Uncertainty in Final Relationship gradient to potentially change the trend direction and invalidate the conclusion is commented	0	The student does not discuss how the magnitude of percentage uncertainty in the final relationship gradient could potentially change the trend direction and invalidate the conclusion. While they mention high uncertainty needs 'careful interpretation,' they don't address potential trend direction changes.
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 student addresses potential concerns that could make results invalid: 'The presence of outlier data points and the variability in light absorption values raise concerns about the consistency and reliability of the results' and discusses factors like 'purity of solvents, precise control of experimental conditions, and potential systematic errors' that might compromise validity.

Evaluation (13 criteria)

Code	Criterion	AI	Justification
EV1	Strengths of methodology are highlighted, based on trial run modifications if possible.	1	The student identifies strengths including multiple trials to minimize random errors, consistent equipment use, and clear trends with no anomalies. They mention modifications from trial runs including standardized staining procedures and controlled conditions.
EV2	Equipment choice is evaluated to reduce Instrumental Uncertainties.	0	While the student mentions equipment choices and suggests graduated cylinders instead of pipettes, they do not identify which equipment contributes the largest instrumental uncertainty or provide detailed analysis of how equipment choices reduce instrumental uncertainties with specific alternative suggestions.
EV3	Comparison of a Mean Propagated % Instrumental Uncertainty vs % Uncertainty in Final Relationship from gradients is stated using [Mean Average IV % un	0	The student calculates propagated instrumental uncertainty as 7.66% but does not provide a clear comparison with the actual percentage uncertainty in the final relationship from gradients. No explicit statement comparing mean average IV + DV uncertainties versus actual uncertainty in final relationship is present.
EV4	Major Methodological improvements suggested to improve accuracy and validity by identifying and removing specific Systematic errors that have become a	0	The student does not identify major systematic errors that would make the experiment potentially invalid, nor do they suggest major methodological improvements to address such systematic errors that became apparent during the experiment.
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 table is present listing weaknesses with a 'relative significance' column that categorizes impacts as high, medium, etc., meeting the requirement for qualitative assessment of each weakness's significance.
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 includes an 'error type' column that correctly identifies random errors, with appropriate descriptions of how random errors produce different magnitudes and directions each time.
EV7	Weaknesses in method are stated in a table with a column for ‘Problems'.	1	The table contains a 'problems' column that clearly identifies and explains specific issues like high uncertainty in repeats, use of pipettes, and measurement increments.
EV8	Weaknesses in method are stated in a table with a column for ‘Suggested Solutions'.	1	The table includes a 'suggested solution' column with actionable recommendations like using graduated cylinders, automated equipment, and equipment with smaller increments.
EV9	Improvements suggest increased Repeated data points and removal of outliers to reduce Random Errors, causing smaller Uncertainty in Repeats.	0	While the student mentions repeated measurements, they do not explain the two distinct processes of how additional data points reduce standard deviation and how this narrower range then allows better outlier identification. The explanation lacks the required depth about these separate mechanisms.
EV10	Improvements suggested to expand the IV data range are made.	0	The student does not suggest specific actual values for expanding the IV data range. No explicit suggestions for changing the polarity range with specific numerical values are provided.
EV11	Improvements suggested to narrow the IV data intervals are made.	0	The student does not suggest specific actual values for narrowing the IV data intervals. No explicit suggestions for reducing interval sizes between polarity values with specific numerical examples are provided.
EV12	Minor Methodological improvements suggested to improve on the accuracy of the experiment.	1	The student suggests minor methodological improvements including using graduated cylinders instead of pipettes, conducting experiments in dark rooms, and standardizing solution transfer procedures, with explanations of how these would improve accuracy.
EV13	Suggested extension investigations, that will adapt and improve this specific investigation are proposed.	0	The suggested extension about investigating how polarity affects plant growth does not build upon the original permanent marker removal experiment. It's in a completely different field rather than adapting and improving the specific investigation of solvent effectiveness in marker removal.