Scientific Investigation and Measurements

Flashcards covering the Scientific Method, experimental design, variables, and the fundamentals of measurements and unit systems.

Scientific Method

A systematic process of empirical investigation used by scientists and engineers to solve problems and organize bodies of knowledge.

Empirical investigation

A process that refers to the use of technology to conduct research and trials.

Statement of a problem

The first step of a scientific investigation which involves choosing a topic and asking questions about why and how things happen.

Hypothesis

A simple statement that presents a possible solution to a problem; it must be testable and based on knowledge and research.

Descriptive statement

A form of hypothesis that provides an overall description of an observation.

Explanatory guess

A form of hypothesis that seeks to clarify the underlying cause of an observed pattern.

Experiment

A set of manipulations or specific observations of nature considered the most important part of the scientific method.

Controlled experiment

An experiment that compares results from an experimental sample against a control sample by looking for changes caused by altering a variable.

Variable

A characteristic, number, or quantity that can be changed or controlled in an experiment and takes different values in different situations.

Controlled Variables

Also known as constant variables, these are factors that are kept constant throughout the experiment and do not undergo treatment.

Independent Variables

Factors that are changed or altered during the experiment to cause corresponding effects in other variables.

Dependent Variables

The variables that are observed as the response to an independent variable, such as plant height or number of leaves.

Natural Experiments

Also known as quasi-experiments, these rely solely on observing the variables of the system under study without investigator manipulation.

Field Experiments

Scientific methods used to examine the real world, frequently applied in social sciences like political science, economics, and psychology.

Control group

The part of the experiment that does not contain the variable being tested.

Experimental group

The part of the experiment that contains the variable being tested.

Conclusion

A concise summary of the experiment's findings that evaluates how results align with the hypothesis by either accepting or rebutting it.

Theory

A scientific explanation for facts or phenomena that has been tested often enough to show valid and reliable results each time.

Measurement

The number of certain dimensions made by comparing a quantity with a standard unit; it consists of a quantity and a unit.

Accuracy

A measure of how close a measurement is to the true or accepted value.

Precision

A measure of how close acquired data points are to each other; small differences between measurements indicate good precision.

SI (Systeme International)

One of the two major systems of measurement currently in use, utilizing a common set of prefixes for multiples.

Kilo (k)

An SI prefix representing a factor of $1,000$.

Length

The distance from one point to another, with the standard SI unit being the meter ($m$).

Mass

An inherent property of an object defined as the measure of the amount of matter it contains, measured in kilograms ($kg$).

Weight

A measure of attraction between two objects due to gravity, which depends on gravitational force.

Thermometry

The scientific measurement of ordinary temperature.

Fahrenheit

The oldest temperature scale, developed by Daniel Fahrenheit in $1724$; formula is $^{\circ}F = (^{\circ}C + 40) \times (9/5) - 40$ or $^{\circ}F = (^{\circ}C + 32)$.

Celsius

A temperature scale devised by Anders Celsius in $1742$ that replaced Fahrenheit for most scientific purposes.

Kelvin

A temperature scale named after the British physicist William "Lord Kelvin" Thomson of Largs.