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Compare and Merge Experiments

Learn how to use the Compare & Merge tool in DORA to evaluate multiple experiments side by side and combine them into a single Merged VPS.

Overview

DORA supports running multiple experiments on the same asset, varying input features, deposit types, or Learning Points to test different geological hypotheses. However, targeting decisions require a single source of truth to act on.

The Compare & Merge tool lets you evaluate those experiments side by side and combine their outputs into a single Merged VPS. You can then generate and evaluate exploration targets directly from that result.

Note: DORA also includes a separate Compare Experiments feature, accessible from the centre toolbar within an experiment. This feature lets you overlay two or more VPS results on a single Prediction Map, but does not provide statistics or allow you to merge results into a single VPS.

In this article:


Preparing Experiments

Before you can compare and merge experiments, all experiments must meet the following conditions:


Starting a Compare & Merge

The Compare & Merge tool is accessed from the DORA index page.

  1. From the main DORA page, select the checkboxes beside at least two experiments you want to compare and/or merge. Their status must be Input Features or Target Generation:

    Select experiments
  2. Click Compare & Merge in the upper right:

    Click Compare & Merge
  3. The Experiment Dashboard opens with the selected experiments loaded.

To add or remove experiments from the dashboard, use the + Add button or click the x beside any experiment tag at the top of the dashboard:

Click the +Add icon


Comparing Experiments

The Compare tab contains five sub-tabs. Each provides a different view of how your experiments relate to each other.

VPS Comparison

Spatial VPS Maps

This tab displays the Prediction Map for each selected experiment side by side. Use the VPS Threshold slider beneath each map to filter the display.

Use this view to spot spatial differences between experiments — for example, whether a change in input features shifted high-VPS areas or produced a different pattern across the Area of Interest (AOI).

VPS Comparison

VPS Distributions

This line chart shows the spread of VPS values across all grid cells for each experiment. Each experiment is represented by its own line.

Use this view to see where most of your VPS values are clustering. A sharp, narrow peak means values are concentrated in a tight range. A flatter, wider curve means values are more spread out across the AOI. Comparing the shapes of the lines helps you assess whether one experiment is producing stronger differentiation between high and low prospectivity areas than another.

VPS Distributions

VPS Statistics

A summary table of key statistics for each experiment's VPS values. For a full explanation of each statistic, see Summary Statistics below.


Performance Breakdown

This tab displays the Performance Breakdown matrix for each selected experiment side by side.

Metric

Definition

F1

Combines Precision and Recall into a single indicator of overall model reliability. A higher value means the model is performing well at identifying prospective areas while avoiding false positives

ACC

Accuracy: The percentage of total predictions the model got correct, across both mineralized and barren locations

PREC

Precision: How often the model is correct when it predicts a location as mineralized

RECALL

Recall: How many of the actual mineralized locations the model successfully identifies

Below the metrics, the Performance Breakdown matrix shows the four prediction outcomes for each experiment:

Label

Definition

True Positive

The model correctly predicted a mineralized location

False Positive

The model incorrectly predicted a mineralized location when it is actually barren

False Negative

The model incorrectly predicted a barren location when it is actually mineralized

True Negative

The model correctly predicted a barren location

Ideally, True Positives and True Negatives should be high, while False Positives and False Negatives should be as low as possible.

Performance Breakdown

Use this tab to compare model reliability across experiments before deciding which to merge. An experiment with a significantly lower F1 or higher False Positive rate may contribute a less reliable signal to the Merged VPS.

For a full explanation of these metrics and how to interpret them, see Prediction Accuracy and Performance Breakdown.


Summary Statistics

This tab displays a bar chart and summary table of VPS score statistics for each experiment.

The Statistics Comparison bar chart plots each statistic as grouped bars, with one colour per experiment, so you can compare experiments across the full range of their score distributions at a glance.

Statistics comparison

The table provides the following statistics for each experiment:

Statistic

Definition

Cell Count

Total number of grid cells scored in the experiment

Min

The lowest VPS score recorded across all grid cells

P25

25% of grid cells score at or below this value

Median

The middle value — half of all grid cells score above this, half below this

P75

75% of grid cells score at or below this value

P90

90% of grid cells score at or below this value — cells above P90 represent the top 10% of prospectivity

Max

The highest VPS score recorded across all grid cells

Mean

The average VPS score across all grid cells

Std

Standard Deviation. Shows how much VPS values vary across the AOI. A higher value means greater spread between high and low values


Pairwise VPS Correlation

This tab shows how similar each pair of experiments is to each other, cell by cell across the shared grid. Scores are colour-coded, and range from -1 to +1:

Value

Definition

1.00

The two experiments produce identical relative scores across the grid

0

No relationship between the two experiments' scores

-1

The experiments produce opposite scores, where one is high, the other is low

Each experiment is perfectly correlated with itself, so the diagonal always shows 1.00. The meaningful values are the remaining cells, each showing the correlation between a pair of experiments.

A lower correlation suggests the experiments are responding to different geological inputs and may produce a more informative Merged VPS when merged. A very high correlation suggests the experiments are similar, and merging them may add limited value.

Pairwise correlation

Feature Importance

This tab shows how input features contributed to each experiment's predictions, allowing you to compare feature influence across experiments side by side.

Feature Importance

Use the Top N Features slider to control how many of the top-ranked input features are displayed in the charts below.

SHAP Feature Importance Comparison

A horizontal bar chart showing the SHAP Contribution % for each input feature, with one bar per experiment. This lets you compare directly how much each feature drove predictions across your selected experiments.

Feature Importance Heatmap

A colour-coded table showing the same SHAP Contribution % data in grid format. Warmer colours indicate a higher contribution. A value of 0.0 means that feature had no influence in that experiment, or was not included as an input feature.

Feature Importance heatmap

Together, these two views help you identify which input features are driving your results and whether that pattern is consistent across experiments, or whether different experiments are responding to different geological signals.

For a full explanation of these metrics and how to interpret them, see Feature Importance.


Merging Experiments

The Merge tab is where you configure and run the experiment merge. Two methods are available:

Method 1: Bayesian Gaussian

The recommended method. Bayesian Gaussian is a statistical method that learns from the Learning Points in each of your selected experiments.

It looks at the VPS values at known positive and negative locations across all selected experiments and uses that information to determine how much weight each experiment's model should carry in the final Merged VPS.

Models that more clearly separate prospective from non-prospective locations carry more influence in the merged result.

Bayesian Gaussian merge option

To merge using the Bayesian Gaussian method:

  1. Select Bayesian Gaussian from the Merge options dropdown.

  2. Review the Learning Points summary cards to confirm the configuration of each experiment.

  3. Under Advanced Settings, set the Balance (negative/positive) value.

    • This setting controls the ratio of negative to positive Learning Points used in the model. Because most datasets have far more negative Learning Points than positive ones, the tool subsamples the negative category to bring it closer to balance. The default value of 1.2 means 1.2 times as many negatives as positives, and is a reliable starting point for most datasets. Increasing this value tunes the model more toward the negative category, which can affect prediction results.

  4. Click Merge Experiments.


Method 2: Simple Average

This method calculates a weighted average of the VPS values from each selected experiment across the shared grid. Equal weights produce a true simple average. You can adjust the sliders to emphasise one experiment over another.

Simple Average merge option

To merge using the Simple Average method:

  1. Select Simple Average from the Merge options dropdown.

  2. Under Experiment Weights, adjust the slider for each experiment. The default weight is 1.0 for all experiments.

  3. The Normalised Weight bar chart updates in real time to show the proportional contribution of each experiment.

  4. Click Merge Experiments.


Reviewing Merge Results

After the merge completes, the Merge tab displays the Training Results.

Column

Definition

New Model Training Accuracy

How accurately the merged model classified positive and negative Learning Points. A higher value indicates a stronger, more consistent signal across the input experiments

Signal Strength

How well that experiment separates prospective from non-prospective areas. A higher value means a clearer signal.

Weight

The share of influence the experiment’s model contributes to the Merged VPS.

Avg Score (Pos)

The average VPS value at positive Learning Point locations for that experiment.

Average Score (Neg)

The average VPS value at negative Learning Point locations for that experiment.

Click See results in the banner to review the full Results tab.


Results

The Results tab displays your Merged VPS and allows you to extract exploration targets.

The following statistics are shown at the top of the page:

Stat

Definition

Cell Count

Total number of grid cells in the Merged VPS

P90 VPS

The VPS score above which only the top 10% of grid cells fall

P75 VPS

The VPS score above which the top 25% of grid cells fall

Median VPS

The middle value across all grid cells

The Merged Spatial Map displays your Merged VPS. Use the VPS Threshold slider under it to filter the display.

The score distribution chart shows the spread of Merged VPS scores, with the individual input experiment distributions overlaid as lines for reference.

Merged Vs Individual Experiments

Target Extraction

Use the Target Extraction section to generate exploration targets from the Merged VPS using spatial clustering.

  1. Set the VPS Threshold to define the minimum VPS value a grid cell must have to be included.

  2. Set the Search Radius (x cell size) to control how far the clustering groups nearby high-scoring cells into a single target.

  3. Set the Min Cells Per Target to define the minimum number of grid cells required to form a target.

  4. Click Generate Target Groups:

    Generate target groups

For a full explanation of Target Groups in DORA, see Create Target Groups.


Target Results

After you click Generate Target Groups, the following summary statistics appear:

Stat

Definition

Targets

Total number of target groups generated

Avg VPS

The average VPS across all generated targets

Largest Target

The number of grid cells in the largest target group

Avg Pred Depth

The average predicted depth across all targets


Risk/Reward Plot

Each target is plotted as a bubble on the Risk / Reward Plot:

  • Y axis - Reward (Merged VPS): Merged VPS for that target. A higher value indicates greater prospectivity.

  • X axis - Risk (Merged VPS Uncertainty): Merged VPS uncertainty for that target. Lower uncertainty indicates that the prediction is better supported. Learn more about uncertainty in DORA.

  • Bubble size: Area of the target.

  • Bubble colour: Priority rating:

    • Very High (green)

    • High (orange)

    • Medium (yellow)

    • Low (grey)

Targets in the upper left of the plot have high prospectivity and low uncertainty — these are your highest priority exploration targets.

Merged Uncertainty values

Click Map to view the same targets overlaid on the Merged VPS Prediction Map.

Click any target to highlight its Mean VPS, grid cell count, and variance in the Target Statistics table.


Target Statistics Table

Column

Definition

Rank

Target priority order, based on VPS score and size

Priority

Categorical rating: Very High, High, Medium, or Low

Cells

Number of grid cells in the target

Area (m²)

Physical area of the target

Centroid X / Y

Geographic centre point of the target

Mean VPS

Average Merged VPS within the target

Max VPS

Highest Merged VPS recorded within the target

Std VPS

How much Merged VPS values vary within the target

Mean Uncertainty

Average Merged VPS Uncertainty within the target

Pred Depth (m)

Average predicted depth of mineralization within the target


Saving and Exporting

To save your Merged VPS to the asset:

  1. Click Save in the lower right on the Results tab:

    Save Results
  2. Name your Merged VPS so it’s easy to identify:

    Name Merged results
  3. Return to the DORA index page. In the upper right, select Merged to see the results in the list:

    Select Merged in upper right

Note: Saved Merged VPS results are visible to all company users with VRIFY Predict access.

To export your Merged VPS for use in GIS or other tools:

  1. Click Export CSV or Download ERS in the lower right on the Results tab:

    Export merged CSV
  2. The file will download automatically to your desktop. Look for the naming convention ensemble_VPS_[number].

    • The .csv contains X, Y, pred_z_merged, VPS_merged, VPS_merged_uncertainty, and target columns.


Tips & Considerations

  • For the most informative Ensemble VPS, consider merging experiments with a lower Pairwise VPS Correlation. Highly correlated experiments may add limited value when merged.

  • The Bayesian Gaussian method is data-driven and recommended in most cases, as the weighting of each experiment’s model is determined by its ability to discriminate prospective from non-prospective areas.

  • When using Simple Average, equal weights are a reasonable starting point. Adjust weights if you have a geological reason to favour one experiment over another.

  • Target Extraction settings will affect the number and size of targets generated. Start with the default values and adjust based on your geological context and scale of interest.


Learn More


Still Have Questions?

Reach out to your dedicated DORA contact or email support@vrify.com for more information.

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