Explore BrainMass

Explore BrainMass

    Accuracy & Precision

    Accuracy and precision, although used interchangeably in the English language, are very different in scientific terms. Accuracy is the closeness of a number of trials to the quantity’s actual value. Precision is the repeated measurements that show similar results. "A measurement system can be accurate but not precise, precise but not accurate, neither or both."¹ A measurement system is valid in a scientific setting if the results are both accurate and precise. Accuracy and precision can be numerically found by the following equations.

    accuracy= (Number of true positives+number of true negatives)/(number of true positives+false positives+false negatives+true negatives )

    precision= (number of true positives)/(number of true positives+false positives )

    Where true and false positives and true and false negatives are denoted by binary classification test.



    1. "Encyclopedia of Psychometrics." Retrieved from http://www.scribd.com/doc/136968050/Encyclopedia-of-Psychometrics

    © BrainMass Inc. brainmass.com May 25, 2020, 4:11 am ad1c9bdddf

    BrainMass Solutions Available for Instant Download

    H1N1 Flue Shot

    Research statistical data that requires a decision. Use probability concepts to formulate your decision. Explain your research methods and process for limiting the uncertainity in the decision. Address: 1) how you applied concpets to formulate your decision. 2) Include appropriate probability concepts and your application t

    Measurements and the Process of Science

    Learning Plan 1. Measurements and the Process of Science Target Competency 1. Apply basic chemistry methods and measurements. (Ch.1) Directions Part A. Choose something to observe in your environment (e.g., sugar dissolving in Kool Aid, pasta cooking, alka seltzer dissolving in water, vinegar reacting with

    Density Measurements from Experimental Data

    Please explain and answer: 1) A student performed an experiment to determine the density of neopentyl alcohol with the following results: Trial 1 Density: 0.815 g/ML Trial 2 Density: 0.932 g/mL Trial 3 Density: 0.691 g/mL (a) Determine the mean and average deviation of these measurements. Are these measurements precise?

    Measurement of physiology

    The axial magnetic field at a distance from a magnet falls-off as l/d3 (note: 3 is the power of d, meaning d cube, it's not multiplying with d) where d is the distance to the magnet. A small, strong, permanent magnet generates a magnetic field that is measured by a small probe placed on its axis. It is desired to use the strengt

    Simple practice questions

    A) "Machine epsilon" is a computer term describing the minimum quantity that can be added to 1 to give a different number. If machine epsilon for a certain computer is 0.000001, roughly how many significant figures does the computer carry in it's calculations? b) To see that it is important to carry more digits in intermedi

    Measurement of the length of something

    A 3.6 cm long radio antenna is added to the front of an aeroplane 41 m long. What is the overall length? Repeat this problem with an aeroplane length of 41.05 m. The answer must be to the correct significant figures. Full details are in the attachment below.

    Sample question to get accustomed to significant numbers.

    Answer the following questions. The answer is to be given to the appropriate significant figures. a) 2.6 x 10 ^5 m + 2.1 x 10 ^ 3 km b) The volume of the moon is 2.21x10^19 m2. What is the radius? c) If there are 100 000 eletronic components on a semiconductor chip that measures 5.0 nm by 5.0 nm      i) How much