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 - this requires experimental investigation beyond simple online searches, is not a standard practical report, has no textbook answers, and extends beyond the syllabus by linking polarity to ink removal efficiency.
RD2	Aim is focused in its breadth, investigating at a single relationship.	1	The aim focuses on a single relationship: how polarity of solvents affects permanent marker removal. While the DV measured is light absorption, this is used to determine removal effectiveness as stated in the aim.
RD3	Aim wording is specific, so the reader knows exactly what the investigation is about.	0	The aim lacks specific details required. It doesn't state the range of polarities being tested, doesn't name the specific solvents (just says 'various solvents'), and doesn't mention any controlled conditions. The research question is more specific but the aim itself is too general.
RD4	Sufficiently appropriate referenced science background affecting the Dependent Variable (DV) to allow understanding of the investigation.	1	The background section explains the science affecting the DV with in-text citations. It discusses polarity, 'like dissolves like' principle, and how light absorption measures ink removal effectiveness. References to 'Frontier' and chemistry principles are present.
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 solvent polarity (IV) affects ink dissolution and thus light absorption (DV). It cites the 'like dissolves like' principle and references sources like 'Frontier' for polarity values, establishing the scientific basis for the IV-DV relationship.
RD6	Valid hypothesis is justified by logical scientific reasoning and the chemistry is accurate and testable by the method.	1	The hypothesis is justified by the background chemistry discussing polar vs non-polar solvents. It specifically predicts polar solvents will be more effective (lower light absorption) while non-polar solvents will show higher lux readings. The chemistry reasoning about 'like dissolves like' supports this.
RD7	Quantitative 'Measurable' Independent Variable (IV) to be manipulated is stated and used consistently when referenced throughout the report.	1	The IV 'polarity of solvents' is stated consistently throughout. While polarity itself is a dimensionless property, the report provides specific numerical polarity values (0.009 for hexane, 0.762 for methanol, etc.) that are measurable and used consistently.
RD8	Quantitative Independent Variable (IV) to be manipulated has correct units stated.	1	The report states polarity values as dimensionless numbers (e.g., 0.009, 0.355, 0.648, 0.654, 0.762), which is correct as polarity indices are dimensionless. The absence of units is appropriate for this property.
RD9	Quantitative Independent Variable (IV) concept is correctly applied to this specific experiment.	1	The IV is correctly applied - using established polarity values for different solvents (hexane 0.009 to methanol 0.762) to test their effectiveness in ink removal. The concept links appropriately to the 'like dissolves like' principle explained in the background.
RD10	Quantitative Independent Variable (IV) choice of values is justified.	1	The choice of solvents is justified: 'these solvents spread across a broad spectrum of polar vs non polar' - selecting solvents ranging from non-polar hexane (0.009) to highly polar methanol (0.762) to test the full range of the polarity spectrum.
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 are NOT in equal intervals: 0.009, 0.355, 0.648, 0.654, 0.762. The intervals are: 0.346, 0.293, 0.006, 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 referred to as 'light absorption' measured in lux throughout the report, from the research question through to the data tables and analysis.
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 data tables and analysis sections.
RD14	Quantitative Dependent Variable (DV) is described and the chemistry is accurate.	1	The DV is accurately described as measuring light absorption through solutions to determine ink removal effectiveness. The chemistry is correct - darker solutions (more ink) absorb more light, resulting in lower lux readings.
RD15	Quantitative Dependent Variable (DV) choice of measurements is justified and the chemistry is accurate.	1	The choice to measure light absorption is justified: 'Higher light absorption indicates a lighter solution, this means less ink was removed, while lower light absorption indicates a darker solution, which means more ink was removed' - explaining why this method effectively measures removal efficiency.
RD16	All Controlled Variables (CV) are identified in a table, with no obvious omissions.	1	All controlled variables are identified in a table format with three columns. Seven CVs are listed: amount of solvent, volume of marker stain, heating time, swirling time, distance from sensor, type of cuvette, and time interval. 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 'Method to control' column that specifies values: 4ml solvent, 45 seconds heating, 30 seconds swirling, 30 cm distance from sensor. Each CV has its maintained value stated.
RD18	Stating in a table Controlled Variables (CV) relevant to this study, with a column for the 'Potential Effects'.	1	The CV table includes 'Possible effects on result' column explaining potential impacts. For example: 'Changing the amount of solvent could affect the concentration of the ink solution, this can lead to inconsistent light absorption readings' - showing specific directional effects on the DV.
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 to control' column with specific control methods. Examples: 'A pipette was used in order to precisely measure and add the same volume of solvent (4ml) to each beaker' and 'Each beaker was heated for the same amount of time (45 seconds) on the bunsen burner.'
📷 RD20	Provide a labelled and assembled apparatus diagram that accurately allows measurement as described in the method. (chemix.org)	1	The student provides a detailed apparatus diagram created in chemix.org showing all necessary components including beakers, cuvettes, light sensor, ruler, pipettes, and solvents. The diagram is properly labeled and shows the experimental setup clearly.
RD21	All Equipment, sizes, absolute uncertainties, and amounts required for the experiment are listed or stated in the Equipment List	0	The equipment list is incomplete. It lists '5 beakers' but doesn't specify the five solvents (ethanoic acid, ethanol, hexane, acetone, methanol) or their concentrations/volumes needed. The method mentions these solvents but they're absent from 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: 'During trial runs, it was noted that variations occurred in the application of the permanent marker stain and in the loss of solvent due to evaporation during heating.' Solutions are justified: 'a more controlled and standardised staining procedure was developed using a template for uniform staining.'
RD23	3rd person, past tense, step-by-step method to carry out the investigation.	0	The method uses past tense correctly but fails to use third person throughout. Examples of first person: 'Before beginning the experiment' instead of 'Before the experiment began'. The method is also in paragraph format, not bullet points as required.
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 provides sufficient detail: specific volumes (4ml solvent), times (45 seconds heating, 30 seconds swirling), distances (15 cm), and step-by-step procedures that would allow replication. Each step explains how variables are controlled.
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 different solvents (ethanoic acid, ethanol, hexane, acetone, methanol) representing five changes to the independent variable (polarity), meeting the minimum requirement.
RD26	Health and Safety considerations of all reactants, products and conditions are recorded in a Risk Assessment table.	0	While there is a 'Risk assessment' table mentioned, it only shows general safety categories (chemical exposure, burns/fire hazards, cuts from glass) without listing specific reactants, products and their individual hazards as required.
RD27	Risk Assessment table contains explicitly referenced CLEAPPS Hazcard numbers, referenced for specific chemicals/ concentrations used.	0	The risk assessment table shows general hazard categories but no CLEAPSS Hazcard numbers are referenced anywhere in the report. The reference '("CLEAPSS Student Safety Sheets")' appears but no specific Hazcard numbers for the chemicals used.
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 only covers hazards, exposure routes, precautions and treatment, but lacks any information about proper disposal of the solvents or waste materials.

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 'Raw Data Table' shows 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.	1	Data table column headings include units in brackets: 'Light absorption of each solution. (lux)' in Table 3.
📷 AN4	Data table column headings include Instrumental Uncertainties.	1	Raw data table includes instrumental uncertainty '± 0.5' after the units for light absorption measurements.
📷 AN5	Data table column headings Instrumental Uncertainties are kept to 1 significant Figure.	0	The instrumental uncertainty is stated as '± 0.5' which has 1 significant figure, but this appears to be inconsistent with the actual instrument uncertainty of ±0.1 lux mentioned elsewhere in the report.
📷 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 columns, appropriate font size, and do not run over page breaks. Tables are easy to read with consistent layout.
AN7	All Instrumental Uncertainties from measuring devices are justified. (Analogue = Half the smallest readable digit, Digital = Smallest Readable digit,	1	The report justifies instrumental uncertainties correctly: ruler ±0.05cm (half smallest digit for analogue), light sensor ±0.1 lux (smallest readable digit for digital), stopwatch ±0.01s (smallest readable for digital), pipette ±0.1mL (smallest readable for digital). Each uncertainty is justified according to whether the instrument is analogue or digital.
📷 AN8	The Decimal Points of raw and processed data are consistent with Instrumental Uncertainties on measurements	0	Raw data values are recorded as whole numbers (e.g., 168, 193) but the instrumental uncertainty is ±0.5 lux, suggesting data should be recorded to 1 decimal place. The decimal points are not consistent with the stated uncertainty.
AN9	Qualitative observations Before, During, and After are recorded that will assist with interpretation.	1	Qualitative observations are recorded for all three phases. Before: 'All the 5 different solvents were colourless, where ethanoic acid had an extremely pungent smell'. During: 'When the beakers were heated...dew drops on the beaker was observed' and detailed color changes for each solvent. After: 'Methanol still continued to be the darkest solution...hexane and ethanoic acid varied but usually remained the lightest'.
📷 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 labeled cuvettes containing different solvents (methanol, acetone, ethanol, hexane), 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 attempts to repeat measurements: 'The measurement was repeated 5 times for each solvent to ensure accuracy and consistency of the data'. This shows clear attempts at repetition to improve reliability.
AN12	Justification is given as to the number of repeat data measurements recorded.	0	No justification is given for why they stopped at 5 repeat measurements. The report states measurements were repeated 5 times but doesn't explain why this specific number was chosen or why they didn't continue taking more measurements.
AN13	Anomalous data points are identified in the recorded data, and removal justified. [No stdv mathematical requirement].	1	The report identifies potential anomalies and justifies their treatment: '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.' They used min/max thresholds to identify outliers.
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 are necessary for this experiment as it directly measures the relationship between polarity (independent variable) and light absorption (dependent variable). Both variables are directly measurable without requiring further calculation.
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 the worked example calculation: 'Worked example = 193.2' which corresponds to hexane with polarity 0.009 (the first row in the raw 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.	0	While a mean value of 193.2 is given, the worked example does not show the actual calculation steps: summing the values (168+193+198+210+197), counting them (5), and dividing (966/5 = 193.2). Only the final answer is provided.
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	A worked example for uncertainty in repeats is provided using the (max-min)/2 formula: 'max value = 224.1, min value = 162.3, uncertainty = (224.1-162.3)/2 = 30.9'. This correctly applies the required formula.
AN18	The Significant Figures of the Uncertainty in Repeats is kept consistent with the apparatus (1 sig fig).	0	The uncertainty in repeats (30.9) is expressed with 3 significant figures, not 1 significant figure as required. It should be rounded to 30 or 3×10¹ to maintain 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	No calculations are shown for mean average % instrumental uncertainty for IV and DV. The report shows individual % uncertainties for various instruments but doesn't calculate the mean change in IV values or mean change in DV values to determine % uncertainties as required.
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%) adds all instrument uncertainties but doesn't follow the required method of adding mean IV % uncertainty + mean DV % uncertainty. The calculation includes controlled variables (beakers) which should not be included.
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 of using the lowest number of decimal places from measuring devices to calculate propagated % uncertainty. The report doesn't show how decimal places affected the calculation of the 7.66% value.
AN22	Mean Propagated % Instrumental Uncertainty is quoted to 1 significant Figure	0	The propagated % instrumental uncertainty (7.66%) is quoted to 3 significant figures, not 1 significant figure as required. It should be rounded to 8%.
📷 AN23	An appropriate sized, scatter graph.	1	The scatter graph in Figure 3 is appropriately sized for the page and uses a suitable scale that represents the data variability without large portions of empty space.
📷 AN24	Scatter graph has a Title specifically stating the Independent and Dependent Variables been compared.	1	The scatter graph has a title 'polarity of solvents vs light absorption (lux)' which specifically states both the independent variable (polarity) and dependent variable (light absorption).
📷 AN25	Scatter graph contains major grid lines.	1	The scatter graph contains major grid lines visible on both axes.
📷 AN26	Scatter graph contains labelled IV vs DV axis labels.	1	The scatter graph has labeled axes with 'Polarity of the solvents' on x-axis and 'light absorption of the solvent (lux)' on y-axis.
📷 AN27	Scatter graph contains IV vs DV 'Measurable' axis units.	1	The scatter graph contains units: y-axis shows '(lux)' for light absorption measurements. The x-axis shows polarity which is dimensionless.
📷 AN28	Scatter graph contains IV vs DV axis Instrumental Uncertainty values.	0	The graph axes do not show uncertainty values. While the text mentions uncertainties, they are not displayed on the axis labels of the graph itself.
📷 AN29	Scatter graph contains uses crosses to plot data points.	0	The scatter graph uses circle markers for data points, not X-shaped cross markers as required.
📷 AN30	A scatter graph trendline gradient equation shows the Final Relationship is given.	1	The scatter graph shows trendline equations: y = -79.673x + 147.49 for the main trendline, showing the final relationship between variables.
📷 AN31	Scatter graph trendline has a R2 value given.	1	The scatter graph displays R² = 0.6824 for the main trendline.
📷 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	Horizontal uncertainty bars for IV are not visible on the scatter graph. The student explains no horizontal bars were used because polarity has no uncertainty, but the criterion requires them to be present or justified.
📷 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 the uncertainty in repeats for the dependent variable (light absorption).
📷 AN34	A Maximium gradient trendline is calculated from the lowest vertical uncertainty bar and highest horizontal uncertainty bar on the first data point, t	0	No maximum gradient trendline is visible on the graph. Only the main trendline and one other trendline are shown, not the required max/min gradient trendlines.
📷 AN35	A Minimum gradient trendline is calculated from the highest vertical uncertainty bar and lowest horizontal uncertainty bar on the first data point, to	0	No minimum gradient trendline is visible on the graph. The graph does not show the required max/min gradient trendlines from uncertainty bar extremes.
📷 AN36	Trendline equations for the Maximum and Minimum gradient trendlines are shown on the graph.	0	Maximum and minimum gradient trendline equations are not shown on the graph. Only the main trendline equation and one other equation are displayed.
AN37	Uncertainty in Final Relationship is calculated by [(Maximum gradient value-minimum gradient value)/2 = Uncertainty in Final Relationship] formula.	0	No calculation shown for uncertainty in final relationship using [(Maximum gradient - minimum gradient)/2]. The report mentions max and min gradients in Table 7 but doesn't show the actual calculation of the uncertainty in the final relationship.
AN38	State Uncertainty in Final Relationship units, using [Y axis units/X axis units] formula.	0	The uncertainty in final relationship units is not stated using [Y axis units/X axis units] formula. The gradient should have units of lux/polarity units, but this is not explicitly stated anywhere in the report.
AN39	State Uncertainty in Final Relationship to 1 Significant Figure	0	The uncertainty in final relationship is not stated to 1 significant figure. In fact, the uncertainty in the final relationship value is not calculated or stated at all in the report.
AN40	Convert Uncertainty in Final Relationship into %Uncertainty in Final Relationship using the [Uncertainty in Final Relationship/Final Relationship grad	0	No calculation shown converting uncertainty in final relationship to % uncertainty using the required formula. The report doesn't show this calculation because the uncertainty in final relationship was never calculated.
AN41	State %Uncertainty in Final Relationship to 1 Signficant Figure	0	The % uncertainty in final relationship is not stated to 1 significant figure because it was never calculated. The report lacks this entire calculation sequence.

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 is based on their scatter graph trendline showing a negative correlation between polarity (IV) and light absorption (DV).
CO2	The IV-DV relationship gradient equation is explicitly stated.	1	The IV-DV relationship gradient equation is explicitly stated in the conclusion: 'Trend 1: y=−79.673x+147.49' where x represents polarity (IV) and y represents light absorption (DV). The equation clearly shows the mathematical relationship between the variables.
CO3	The IV-DV relationship gradient units are quoted in the conclusion.	0	While the gradient value (-79.673) is mentioned, the units for this gradient are not explicitly stated in the conclusion. The gradient units should be lux per unit of polarity, 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 comments on the R² value (0.6824) and categorizes it correctly: 'the R² value of 0.6824 indicates a moderately negative correlation between solvent polarity and light absorption.' This falls within the 0.3-0.7 range for moderate correlation as required.
CO5	Accuracy of relationship is justified based on cited research of a similar area of study.	1	The student justifies the accuracy of the relationship 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, thus having a affect on light absorption properties.' This includes proper references in the reference list.
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 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.' The student explains the underlying chemistry related to polar solvents' effectiveness.
CO7	% Uncertainty in Final Relationship from min-max trendlines is re-stated in the Conclusion.	0	The % uncertainty in the final relationship from min-max trendlines is not stated in the conclusion. While propagated instrumental uncertainty (7.66%) is mentioned, this is different from the uncertainty in the final relationship gradient calculated from max/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	While the student mentions 'The relative high percentage uncertainty of 7.66% indicates that while the trends that are observed are informative, this needs to be interpreted with caution,' they do not specifically discuss whether this uncertainty magnitude could potentially change the trend direction or invalidate the conclusion.
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 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.' They discuss potential issues with experimental conditions and measurement techniques that could compromise validity.

Evaluation (13 criteria)

Code	Criterion	AI	Justification
EV1	Strengths of methodology are highlighted, based on trial run modifications if possible.	1	The report clearly identifies strengths including 'Multiple trials for each solvent were done in order to minimise random errors' and 'The consistent use of a light sensor with an uncertainty of ±0.1 lux and beakers with ±5% uncertainty helped maintain accuracy'. It also mentions trial run modifications: 'During trial runs, it was noted that variations occurred... To address these issues, a more controlled and standardised staining procedure was developed using a template for uniform staining.'
EV2	Equipment choice is evaluated to reduce Instrumental Uncertainties.	1	The report evaluates equipment choice and identifies pipettes as having the largest instrumental uncertainty: 'improvement- graduated pipettes or cylinders could have been used instead of a normal pipette... This could have been one of the reasons behind having a high percentage uncertainty'. It suggests alternative equipment (graduated cylinders) that would reduce instrumental uncertainties.
EV3	Comparison of a Mean Propagated % Instrumental Uncertainty vs % Uncertainty in Final Relationship from gradients is stated using [Mean Average IV % un	0	While the report calculates propagated instrumental uncertainty (7.66%) and mentions uncertainty in repeats, it does not provide the required comparison format of (Mean Average IV % uncertainty + Mean Average DV % Uncertainty) vs actual % Uncertainty in Final Relationship from gradients. The report lacks explicit calculation of mean IV and DV percentage uncertainties.
EV4	Major Methodological improvements suggested to improve accuracy and validity by identifying and removing specific Systematic errors that have become a	0	The report does not identify any MAJOR systematic errors that would make the experiment potentially invalid. While it mentions methodological improvements, these are minor refinements rather than addressing critical systematic errors that undermine 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	0	The weaknesses table uses 'relative significance' column but with incorrect categories (high/medium instead of minor/moderate/major/critical). The table shows: 'relative significance' with values 'high' and 'medium', not the required qualitative assessment scale.
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 weaknesses table includes an 'error type' column with errors correctly identified as 'random'. Each error is appropriately categorized - 'high uncertainty in repeats' and 'use of pipettes' are correctly identified as random errors that would produce varying deviations.
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 report mentions 'repeated measurements were taken to ensure reliability', it does not discuss the two distinct processes required: 1) how additional data points lead to lower standard deviation, and 2) how this narrower data range allows for outlier identification. The report simply states 'removal of outliers wasn't necessary due to the absence of anomalies'.
EV10	Improvements suggested to expand the IV data range are made.	0	The report mentions 'modifying the independent variable's data range and intervals to enhance resolution' but does not provide specific actual values for the expanded IV range. A general statement about expanding data range is insufficient according to the criteria.
EV11	Improvements suggested to narrow the IV data intervals are made.	0	Similar to EV10, the report only makes a general statement about 'modifying the independent variable's data range and intervals' without suggesting specific actual values for narrowing the intervals or comparing with existing IV values.
EV12	Minor Methodological improvements suggested to improve on the accuracy of the experiment.	1	The report suggests specific minor methodological improvements: 'The utilisation of graduated cylinders or burette instead of pipettes', 'could have tried to do this experiment in a dark room', and 'Standardise the procedure for transferring solutions to cuvettes'. These are feasible enhancements specific to this experiment with explanations of how they would improve accuracy.
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 not appropriately linked to the original experiment. This is similar to the inappropriate example given in the criteria - it's in a related field but doesn't actively build upon the existing experiment to help find the aim more accurately. There's no justification for how this would help the research of the original investigation about marker removal.