Accuracy

Accuracy is the degree to which the measurement resembles the true value. Accuracy is one example of good measurement quality. When buying a pound of bread from a supermarket, we can say that the measurement is accurate if the weight of the pound matches the printed values.

Although it is not computed directly, accuracy can be computed using the errors. High accuracy is indicated by a measurement with few errors.

The following percent error formula determines the accuracy:

\(Percent \ error={\frac {(measured \ value\ -\ true \ value)}{true \ value}} × 100\)

This formula gives the accuracy as a percentage. A smaller percent error means a more accurate result.

What are the types of accuracy?

A system’s accuracy can be classified into three types, they are:
 

1. Point accuracy
    
2. Accuracy as percentage of scale range
    
3. Accuracy as percentage of true values

Point accuracy: The accuracy of an instrument at a particular point on its scale is referred to as point accuracy. It doesn’t represent the instrument’s overall accuracy over its whole range. It merely indicates that an instrument’s accuracy refers to how close its measurement is to the true value at a given time.

Accuracy as percentage of scales range: The consistency of the instrument’s scale is the foundation for this kind of accuracy. Take a thermometer with a scale that goes up to 100°C. If it has an accuracy of ± 0.5, it means the reading could be off by up to ±0.5°C. For example, A thermometer with ± 0.5% accuracy on a 100°C scale means it can be off by up to  ±0.5°C (0.005 × 100 = ±0.5 °C). So, any reading may be 0.5 °C.

Accuracy as percentage of true values: This accuracy metric evaluates the degree to which the measured value resembles the true value. Instruments usually have an acceptable margin of error, usually ±0.5 percent of the actual value. This criterion helps in assessing an instrument’s accuracy with regard to the object it is measuring.

To determine whether our data is accurate, the following actions can be taken:

Step 1: Collect and organize data 

Step 2: Determine the mean value.

Average value = sum of data number of measurements

Step 3: Determine the percentage of error.

Percent error = accepted value - measured value accepted value× 100

Step 4: Find the absolute deviations for each measurement, using the formula.

Absolute deviation = measured value - average value

Step 5: Calculate the average of all deviations.

The average deviation is calculated by adding the absolute deviations of all the measurements together and dividing the result by the total number of measurements.

The following elements should be considered when assessing the precision of our data:

Error types: Accuracy can be evaluated by analyzing different types of errors. It shows how much the measured data deviates from the actual values. Two common ways to assess accuracy are by calculating the errors.
 

Absolute error: The absolute error is the discrepancy between a measured value and an actual value. You may be able to ascertain how closely your measurement corresponds to the item’s actual value by looking at the absolute error.

Absolute error = Measured value - Actual value

Relative error: This shows how much the measurement itself deviates from the absolute error. This can be helpful when determining the magnitude of the error relative to the actual value. Our measurement is usually accurate if the relative error is smaller.
Relative error = {Absolute error} {Measured value}
 

Tools of measurement: One factor that may have an impact on the accuracy of our findings is the measurement techniques we use when gathering data. Measurement devices that can gather data in smaller steps tend to produce more accurate results.

Significant figures: When measuring accuracy, it is important to consider that the significant figures are the digits in a measurement that contribute to its accuracy. When collecting data, you can only record the number of digits that your measurement equipment can handle.

Here are some of the tips and tricks to master the concepts of accuracy.
 

1. Understand before you solve. Never rush to plug in numbers. Read the question twice and underline keywords like sum, difference, coefficient, total, etc. Ask yourself, “What is this question really asking me to find?”
    

2. Show every step clearly. Write each step neatly, even if you can do it in your head. This helps catch small sign or operation errors (like confusing + and –). Use one line per logical step.
    

3. Slow down during operations. Accuracy is about attention, not speed. For multistep problems, double-check each operation before moving to the next. Example: Re-add totals after combining terms in algebraic expressions.
    

4. Keep formulas handy. Maintain a “Formula Flash Sheet” for quick reference. Reviewing it often ensures you don’t mix up similar-looking formulas (like area vs perimeter).
    

5. Review your mistakes. When you get something wrong, don’t erase immediately. Instead, note why it was wrong (Carelessness? Misunderstanding? Formula misuse?). Build a “Common Mistakes List,” a personal tool to avoid repeating them.

Accuracy in real life means how close a measured value is to the true value. Let us see how accuracy helps in real life.
 

1. Calibration of medical thermometers: A thermometer is used in hospitals to measure a patient’s body temperature. If it shows a 98.6°F result for a healthy person, it is considered accurate. This accuracy helps doctors make correct diagnoses and avoid false symptoms.
    
2. GPS location monitoring: A delivery app uses the GPS to track the driver’s location. If the pin shows the driver exactly at your doorstep. The system is considered accurate. This level of accuracy helps ensure on-time deliveries and a better customer experience.
    
3. Laboratory test results: The equipment and technique employed in a diagnostic lab are accurate if a blood test correctly indicates the patient’s blood sugar level as 90 mg/dL, when that is the actual value. This promotes appropriate medical care.
    
4. Weighing products in stores: Fruits are weighed on digital scales at a supermarket. The scale is accurate if 1 kg of apples is put in, and it reads 1 kg. Fair pricing and client trust are thus guaranteed.
    
5. Sports timing devices: The timing system records an athlete’s time at the end of a 100-meter race as 9.58 seconds, which is precisely the same as the official record and the manual stopwatch. This demonstrates that the timing system meets competition standards for accuracy and dependability.