Lesson 2: ACCURACY and PRECISION

What is Measurement?

process of quantifying the attributes of an object or event, such as its size, weight, capacity, or other aspect.

What is Qualitative data?

These are Descriptive, non-numerical data (e.g., color, phase, texture).

What is Quantitative?

These are Numerical data with units.

Standard Temperature and Pressure is important because?

Ensures precision and accuracy for reliable data collection.

What is Mass?

It Describes the quantity of matter in an object.

What is Accuracy?

Proximity of measured values to the actual (true) value.

What is Precision?

Consistency of measurements over multiple trials.

How do we determine accuracy in measurement?

Compare with reference standards; computation of percentage error; Bland-Altman Plot.

How do we determine precision in measurement?

Computation of repeatability (standard deviation or coefficient of variation), scatter analysis.

It is the Misalignment of the eye with the meniscus during measurement when using pipette.

Parallax Error

It is the error due to Incomplete drainage and liquid adhering to the inner walls; improper pipetting technique.

Delivery Technique

Error due to difficulty in aligning the eye to the lowest point of the liquid's meniscus using the graduated cylinder.

Meniscus Reading Error

Graduated cylinders have fewer and broader volume divisions, leading to estimation inaccuracies. What type of error it is?

Wider Markings

If graduated cylinder are not properly clean. The residual droplets from previous liquids can affect measurements. This error is called?

Irregular Cleaning