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 question about how solvent polarity affects permanent marker removal is not directly answerable through simple online search, not a standard practical report, not in textbooks, and not self-evident from the syllabus. It requires experimental investigation to determine the relationship.
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). No multiple relationships are mentioned.
RD3	Aim wording is specific, so the reader knows exactly what the investigation is about.	0	The aim lacks specificity - it does not state the specific IV range (0.009-0.762) or the specific solvents being tested. The reader cannot know exactly what the investigation covers without reading further.
RD4	Sufficiently appropriate referenced science background affecting the Dependent Variable (DV) to allow understanding of the investigation.	0	The background section lacks sufficient chemistry detail about light absorption. It mentions the 'like dissolves like' principle but doesn't explain the specific chemistry of how dissolved ink affects light transmission/absorption or provide referenced scientific explanations for the DV measurement principle.
RD5	Sufficiently appropriate referenced science background explaining how the Independent Variable (IV) will potentially cause changes in the measured Dep	0	While the background discusses polarity affecting dissolution, there is no in-text citation supporting how polarity changes will specifically affect light absorption measurements. The connection between IV and DV lacks referenced scientific support.
RD6	Valid hypothesis is justified by logical scientific reasoning and the chemistry is accurate and testable by the method.	0	The hypothesis contains a chemistry error - it states non-polar solvents will 'absorb the most light' and have 'highest lux readings' which is contradictory. High lux means more light transmission, not absorption. The hypothesis also predicts opposite trends for the same phenomenon.
RD7	Quantitative 'Measurable' Independent Variable (IV) to be manipulated is stated and used consistently when referenced throughout the report.	0	The IV is inconsistently referenced throughout - sometimes as 'polarity' without values, sometimes with values (0.009), sometimes as solvent names (hexane) without consistent inclusion of polarity values. The quantitative aspect is not maintained consistently.
RD8	Quantitative Independent Variable (IV) to be manipulated has correct units stated.	0	The report never explicitly states that polarity is dimensionless or discusses its units. While polarity values are given, the lack of unit discussion or explanation that it's dimensionless fails to meet the criterion.
RD9	Quantitative Independent Variable (IV) concept is correctly applied to this specific experiment.	1	The quantitative IV (polarity) is correctly applied to this experiment. The student correctly identifies polarity as the manipulated variable and links it appropriately to the dissolution and removal of permanent marker ink.
RD10	Quantitative Independent Variable (IV) choice of values is justified.	0	The justification states solvents were chosen to 'spread across a broad spectrum of polar vs non polar' but doesn't explain why these specific polarity values (0.009, 0.355, 0.648, 0.654, 0.762) were selected or justify each individual value.
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 IV intervals are not equal: 0.009 to 0.355 (0.346), 0.355 to 0.648 (0.293), 0.648 to 0.654 (0.006), 0.654 to 0.762 (0.108). No justification is provided for these unequal intervals.
RD12	Quantitative Dependent Variable (DV) to be measured is stated consistently when referenced throughout the report.	1	The DV is consistently stated as 'light absorption' measured in lux throughout the report. The terminology remains consistent from introduction through conclusion.
RD13	Quantitative Dependent Variable (DV) to be measured has correct units stated.	1	The DV units are correctly stated as lux (lx) in the variables table and used consistently throughout the report.
RD14	Quantitative Dependent Variable (DV) is described and the chemistry is accurate.	1	The DV is accurately described as light absorption measured using a light sensor, with correct chemistry understanding that darker solutions (more ink dissolved) absorb more light and give lower lux readings.
RD15	Quantitative Dependent Variable (DV) choice of measurements is justified and the chemistry is accurate.	0	While the report states light absorption is measured, it doesn't justify why this specific method was chosen over other possible methods like spectrophotometry, colorimetry, or direct measurement of ink remaining on the surface.
RD16	All Controlled Variables (CV) are identified in a table, with no obvious omissions.	0	The CV table has obvious omissions including: light source intensity/type (only mentions 'phone torch'), ambient light conditions, cuvette path length, solution temperature, and specific marker brand/type used.
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 'Method to control' column that specifies values maintained: 4ml solvent volume, 45 seconds heating time, 30 seconds swirling time, 30cm distance from sensor.
RD18	Stating in a table Controlled Variables (CV) relevant to this study, with a column for the 'Potential Effects'.	0	The 'Possible effects on result' column doesn't specify the direction of DV change. For example, it states 'different amounts of light being absorbed' but doesn't specify whether more/less solvent would increase/decrease absorption.
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 a 'Method of Control' column with specific methods for each variable, such as using a pipette for 4ml volumes, heating for 45 seconds, and maintaining 30cm distance with a ruler.
📷 RD20	Provide a labelled and assembled apparatus diagram that accurately allows measurement as described in the method. (chemix.org)	1	Figure 1 shows a detailed apparatus diagram from chemix.org with all equipment labeled and assembled in measurement positions: beakers with solvents, cuvettes positioned for measurement, light sensor, ruler showing 15cm distance, and pipettes for transferring solutions.
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 required details: no specific permanent marker brand/type, no concentrations for pure solvents, cuvette specifications missing (path length, material), light sensor model/specifications not provided.
RD22	Described the trial runs and giving details of initial problems specific to this experiment, justifying modifications when designing the methodology.	1	The report describes trial run problems: 'variations occurred in the application of the permanent marker stain and in the loss of solvent due to evaporation during heating' and explains how these were addressed with a standardized staining procedure.
RD23	3rd person, past tense, step-by-step method to carry out the investigation.	0	The method is not written in third person past tense throughout. It uses passive voice ('were selected', 'was marked') but also includes instructions like 'A light sensor was calibrated' which should be 'The light sensor was calibrated by the researcher'.
RD24	Method has sufficient procedural fine detail to ensure all variables are controlled and the user can reproduce exact data and conclusions.	0	The method lacks procedural detail for reproduction: no specific marker stroke pattern/pressure, 'around 30 seconds' and 'about 45 seconds' are imprecise, no detail on how solutions were 'carefully poured' into cuvettes, calibration procedure not explained.
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 exactly five changes to the independent variable (five different solvents with polarities: 0.009, 0.355, 0.648, 0.654, 0.762).
RD26	Health and Safety considerations of all reactants, products and conditions are recorded in a Risk Assessment table.	0	While a Risk Assessment table is mentioned as 'Table2', the actual table content shows general categories (chemical exposure, burns, cuts) but doesn't list specific reactants/products like ethanol, acetone, methanol, hexane, and ethanoic acid individually.
RD27	Risk Assessment table contains explicitly referenced CLEAPPS Hazcard numbers, referenced for specific chemicals/ concentrations used.	0	The report mentions 'source from CLEAPSS Student Safety Sheets' but no specific Hazcard numbers are provided for any of the chemicals used (ethanol, acetone, methanol, hexane, ethanoic acid).
RD28	Risk Assessment table contains explicitly referenced CLEAPPS Hazcard numbers, referenced for specific disposal of materials used or produced.	0	No disposal methods are mentioned in the risk assessment table. The table shows treatment for accidents but not proper disposal procedures for the solvents or ink solutions as per CLEAPSS guidelines.

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 IV (polarity of solvent) in the first column and DV repeats (trials 1-5 of light absorption) in subsequent columns to the right.
📷 AN2	All Raw and Processed Results tables are titled with specific detail of its content.	1	Tables are titled with specific detail: 'Table 3. Raw Data Table', 'Table 5. Average, Max, Min and Standard deviation for each sample', 'Table 6. Processed Data table including the average of light absorption of each solvent (lux)', 'Table 7: processed data table of uncertainty in final relationship'.
📷 AN3	Data table column headings include 'Measurable' units.	0	Table 3 column headings lack units in brackets. Headers show 'polarity of the solvent' and 'trial 1' etc. without units. Should be 'polarity of the solvent (dimensionless)' and 'Light absorption (lux)'.
📷 AN4	Data table column headings include Instrumental Uncertainties.	0	Raw data table (Table 3) column headings do not include instrumental uncertainties. The table title mentions '(lux) ± 0.5' but this is not in the actual column headings where it should be.
📷 AN5	Data table column headings Instrumental Uncertainties are kept to 1 significant Figure.	1	The instrumental uncertainty shown is ± 0.5 lux, which is correctly expressed to 1 significant figure.
📷 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	Tables are well-formatted with adequate spacing, legible font size, and do not run over page breaks. Column widths are sufficient to display data clearly.
AN7	All Instrumental Uncertainties from measuring devices are justified. (Analogue = Half the smallest readable digit, Digital = Smallest Readable digit,	1	The student correctly justifies all instrumental uncertainties: ruler ±0.05cm (half smallest division), light sensor ±0.1 lux (digital), stopwatch ±0.01s (digital), pipette ±0.1mL, and beakers ±5%. Each uncertainty is properly explained based on instrument type.
📷 AN8	The Decimal Points of raw and processed data are consistent with Instrumental Uncertainties on measurements	0	Raw data recorded as whole numbers (168, 193, etc.) but instrumental uncertainty is ±0.5 lux, so data should be recorded to 1 decimal place (168.0, 193.0, etc.).
AN9	Qualitative observations Before, During, and After are recorded that will assist with interpretation.	1	Detailed qualitative observations are recorded for all three phases. Before: 'colourless solvents, ethanoic acid had pungent smell, dry beaker bottoms'. During: 'evaporation with dew drops observed, color changes noted for each solvent'. After: 'Methanol darkest, hexane lightest, acetone neutral'. These complement the measured data.
📷 AN10	Qualitative observations are backed up by photographic evidence of the experiment	1	First photograph shows physical setup with labeled beakers, cuvettes, and equipment. This provides photographic evidence of the actual experimental setup.
AN11	Attempts are made to repeat measurements, until they are within the Instrumental Uncertainty limits set out by the apparatus.	1	The student explicitly states 'The measurement was repeated 5 times for each solvent to ensure accuracy and consistency of the data' and acknowledges that 'The uncertainty of 7.66% is relatively high' showing awareness that variation exceeded instrumental uncertainties despite attempts.
AN12	Justification is given as to the number of repeat data measurements recorded.	0	While the student mentions '5 times for each solvent to ensure accuracy', there is no justification for WHY they stopped at 5 repeats. No discussion of time constraints, consistency of results, or other factors that led to choosing 5 repeats specifically.
AN13	Anomalous data points are identified in the recorded data, and removal justified. [No stdv mathematical requirement].	1	The student identifies potential anomalies using min/max thresholds: '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.'
AN14	If the experiment requires any processing through additional equations, then any necessary calculations in order to process data are complete and with	1	No additional equations were needed for this experiment as light absorption was directly measured in lux. The student measures the relationship between polarity (independent variable) and light absorption (dependent variable) directly without requiring processing calculations.
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 student clearly states they will use the first IV value for the worked example: 'the uncertainty of the vertical error bar for hexane (0.009)' where hexane with polarity 0.009 is the first value in their data table.
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	A complete worked example is provided for hexane: 'Worked example = (168+193+198+210+197)/5 = 193.2'. The calculation shows summing the five values (966 total) and dividing by 5 to get the mean of 193.2.
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 worked example for uncertainty in repeats is given: 'max value = 224.1, min value = 162.3, uncertainty = (224.1-162.3)/2 = 30.9'. The formula (Max-Min)/2 is correctly applied to the first IV data set.
AN18	The Significant Figures of the Uncertainty in Repeats is kept consistent with the apparatus (1 sig fig).	0	The uncertainty in repeats for hexane is stated as 30.9, which has 3 significant figures, not 1. It should be rounded to 30 or 3×10¹ to maintain 1 significant figure consistency with apparatus precision.
AN19	Calculate a Mean Average % Instrumental Uncertainty from both IV and DV data using the following formula: [Instrumental uncertainty/Mean change in IV	0	The student calculates individual % uncertainties for each device but does not calculate mean average % uncertainties for IV and DV as required. They show ruler 0.55%, light sensor 0.1%, stopwatch 0.01%, pipette 2%, beakers 5%, but don't average IV and DV uncertainties separately.
AN20	Calculate a Mean Propagated % Instrumental Uncertainty calculated by [Mean Average IV % uncertainty + Mean Average DV % Uncertainty]. Addition of all	0	The propagated uncertainty calculation (7.66%) incorrectly includes ALL equipment uncertainties including controlled variables. The criterion requires only IV and DV measuring devices. Polarity (IV) has no uncertainty and light sensor (DV) is 0.1%, so propagated uncertainty should be much lower.
AN21	Mean Propagated % Instrumental Uncertainty is calculated using the lowest numbers of Decimal Places on any of the different Measuring Device Instrumen	0	No evidence that the propagated uncertainty calculation considers the lowest number of decimal places among measuring devices. The calculation simply adds percentages without addressing decimal place limitations.
AN22	Mean Propagated % Instrumental Uncertainty is quoted to 1 significant Figure	0	The propagated instrumental uncertainty is stated as 7.66%, which has 3 significant figures. It should be rounded to 8% to maintain 1 significant figure as required.
📷 AN23	An appropriate sized, scatter graph.	1	Figure 3 scatter graph is appropriately sized, fills most of the plotting area without large empty spaces, and uses suitable scale from 0-250 lux and 0-1 polarity.
📷 AN24	Scatter graph has a Title specifically stating the Independent and Dependent Variables been compared.	1	Graph title 'polarity of solvents vs light absorption (lux)' explicitly states both independent variable (polarity of solvents) and dependent variable (light absorption).
📷 AN25	Scatter graph contains major grid lines.	1	Figure 3 clearly shows major grid lines on both x and y axes forming a visible grid pattern across the plotting area.
📷 AN26	Scatter graph contains labelled IV vs DV axis labels.	1	Graph axes are labeled with 'Polarity of the solvents' on x-axis and 'light absorption (lux)' on y-axis, clearly identifying IV and DV.
📷 AN27	Scatter graph contains IV vs DV 'Measurable' axis units.	1	Y-axis labeled 'light absorption (lux)' includes the unit. X-axis shows 'Polarity of the solvents' which is dimensionless.
📷 AN28	Scatter graph contains IV vs DV axis Instrumental Uncertainty values.	0	Axis labels do not include uncertainty values. Should show 'light absorption (lux) ± varies' on y-axis. Student explains polarity has no uncertainty but this explanation should be on the axis label.
📷 AN29	Scatter graph contains uses crosses to plot data points.	1	Figure 3 clearly shows X-shaped crosses for all data points, not circles or dots.
📷 AN30	A scatter graph trendline gradient equation shows the Final Relationship is given.	1	Graph shows trendline equation y = -79.673x + 147.49 where the gradient -79.673 quantifies the final relationship between polarity and light absorption.
📷 AN31	Scatter graph trendline has a R2 value given.	1	Graph displays R² = 0.6824 next to the main trendline equation.
📷 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	0	No horizontal uncertainty bars visible on graph. Student states polarity has no uncertainty, but this should be shown or explicitly noted on the graph itself.
📷 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 clearly visible on all data points in Figure 3, representing the calculated uncertainty in repeats for each solvent.
📷 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 visible on graph starting from lowest point of first error bar to highest point of last error bar with equation shown.
📷 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 visible on graph starting from highest point of first error bar to lowest point of last error bar with equation shown.
📷 AN36	Trendline equations for the Maximum and Minimum gradient trendlines are shown on the graph.	1	Both max and min gradient trendline equations are displayed on the graph along with the main trendline equation.
AN37	Uncertainty in Final Relationship is calculated by [(Maximum gradient value-minimum gradient value)/2 = Uncertainty in Final Relationship] formula.	0	No calculation of uncertainty in final relationship using the (Max gradient - Min gradient)/2 formula is present. The student shows max and min data in a table but doesn't calculate the gradient uncertainty.
AN38	State Uncertainty in Final Relationship units, using [Y axis units/X axis units] formula.	0	The uncertainty in final relationship is not stated with proper units. The gradient units should be lux per polarity unit, but this is never explicitly stated in the report.
AN39	State Uncertainty in Final Relationship to 1 Significant Figure	0	Since the uncertainty in final relationship was not calculated (AN37), it cannot be stated to 1 significant figure. This criterion cannot be met without completing the previous calculation.
AN40	Convert Uncertainty in Final Relationship into %Uncertainty in Final Relationship using the [Uncertainty in Final Relationship/Final Relationship grad	0	No calculation converting uncertainty in final relationship to percentage uncertainty is present. The formula [Uncertainty in Final Relationship/Final Relationship gradient value x 100] is not applied.
AN41	State %Uncertainty in Final Relationship to 1 Signficant Figure	0	Since the % uncertainty in final relationship was not calculated (AN40), it cannot be stated to 1 significant figure. This criterion depends on completing the previous calculation.

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 gradient trend in the conclusion: 'The relationship that was observed showed that as the polarity increased, light absorption would decrease.' This describes a negative gradient trend based on their trendline analysis.
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' where y represents light absorption and x represents polarity. These are clearly stated mathematical equations showing the IV-DV relationship.
CO3	The IV-DV relationship gradient units are quoted in the conclusion.	0	While the student states gradient values (-79.673 and -57.371), they do not explicitly state the units of these gradients in the conclusion. The units should be lux per unit polarity (or similar), but this is not mentioned anywhere in the conclusion section.
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 the R² values and categorizes them: 'R² value of 0.6824 indicates a moderately negative correlation' for Trend 1. While they don't use the exact terminology of 'moderate 0.3-0.7', they correctly interpret 0.6824 as indicating a moderate correlation strength.
CO5	Accuracy of relationship is justified based on cited research of a similar area of study.	1	The student cites relevant research: 'Studies on the various effects of solvent polarity on photochemical reactions demonstrate that more polar solvents facilitate better interactions with solute molecules, thus having a affect on light absorption properties.' This is appropriately related to their investigation without being too similar to suggest plagiarism.
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 and compares it with results: 'The hypothesis of this experiment stated that polar solvents would be more effective in removing the ink...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.' They reference the underlying chemistry of polar solvents being more effective at ink removal.
CO7	% Uncertainty in Final Relationship from min-max trendlines is re-stated in the Conclusion.	0	The student mentions 'The relative high percentage uncertainty of 7.66%' but this is the propagated instrumental uncertainty, not the % uncertainty in the final relationship from min-max trendlines. The % uncertainty from gradient variation should be calculated from the difference between max and min gradients, which is not presented in the conclusion.
CO8	The magnitude of the %Uncertainty in Final Relationship gradient to potentially change the trend direction and invalidate the conclusion is commented	0	While the student mentions the 7.66% uncertainty and says it 'needs to be interpreted with caution', they do not specifically discuss whether this uncertainty magnitude could potentially change the trend direction (from negative to positive) and invalidate their conclusion about polarity's effect on light absorption.
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 comments on validity concerns: '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'. They acknowledge issues that could affect 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 use of equipment to eliminate variation, and specific equipment uncertainties (light sensor ±0.1 lux, beakers ±5%). They also mention modifications from trial runs where they developed a standardized staining procedure using a template for uniform staining.
EV2	Equipment choice is evaluated to reduce Instrumental Uncertainties.	1	The student evaluates equipment choice by identifying the pipette as having the largest instrumental uncertainty and suggests using graduated pipettes or cylinders instead to reduce volume measurement errors. They provide specific uncertainty values (±0.1 mL for pipette) and explain how this contributed to the high 7.66% uncertainty.
EV3	Comparison of a Mean Propagated % Instrumental Uncertainty vs % Uncertainty in Final Relationship from gradients is stated using [Mean Average IV % un	1	The student explicitly calculates and compares the mean propagated instrumental uncertainty (7.66%) versus the uncertainty in final relationship. While they don't provide a single percentage for the final relationship uncertainty, they discuss how the 7.66% is relatively high and exceeds the 5% threshold, leading into discussion of potential flaws.
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 any MAJOR systematic errors that would make the experiment potentially invalid. They discuss methodological improvements like using graduated cylinders and conducting the experiment in a dark room, but these are minor improvements rather than corrections to major systematic errors undermining 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	The student presents a table with weaknesses in method including a 'relative significance' column. They classify errors as 'high' (high uncertainty in repeats), 'medium' (use of pipettes, measurement increments), showing appropriate assessment of impact levels.
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 where errors are correctly classified as 'random'. The student correctly identifies that these errors (high uncertainty, pipette use, measurement increments) would produce varying magnitudes and directions, consistent with random error classification.
EV7	Weaknesses in method are stated in a table with a column for ‘Problems'.	1	The table clearly has a 'problems' column that identifies and explains specific issues: 'high uncertainty in repeats', 'use of pipettes', and 'measurement increments'. Each problem is clearly articulated with explanations provided.
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 solutions for each weakness: 'Conduct thorough analysis of experimental procedure and standardise conditions. Use automated equipment', 'use graduated cylinders instead', and 'Use equipment with smaller measurement increments for more accurate readings'.
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 were taken to ensure reliability', they only state that 'removal of outliers wasn't necessary due to the absence of anomalies'. They don't explain the two-step process of how additional data points would reduce standard deviation first, then allow for identification of outliers in a narrower range.
EV10	Improvements suggested to expand the IV data range are made.	0	The student mentions 'modifying the independent variable's data range and intervals to enhance resolution' but fails to provide specific actual values for the expanded range. They don't suggest specific polarity values beyond the current 0.009-0.762 range.
EV11	Improvements suggested to narrow the IV data intervals are made.	0	Similar to EV10, the student mentions 'modifying the independent variable's data range and intervals' but doesn't provide specific values for narrower intervals between the current polarity values (0.009, 0.355, 0.648, 0.654, 0.762).
EV12	Minor Methodological improvements suggested to improve on the accuracy of the experiment.	1	The student suggests minor methodological improvements specific to this experiment: using graduated cylinders/burettes instead of pipettes for better accuracy, conducting the experiment in a dark room to control ambient light, and standardizing the procedure for transferring solutions to cuvettes.
EV13	Suggested extension investigations, that will adapt and improve this specific investigation are proposed.	0	The suggested extension 'investigate how varying polarity will affect plant growth' is a completely different experiment rather than building upon this specific investigation about marker removal. It doesn't help achieve the aim of finding marker removal effectiveness more accurately.