Scientific Method & Significant Figures - Vocabulary

Vocabulary flashcards covering the key concepts from the lecture notes on the scientific method and significant figures.

Scientific Method

A systematic, step-by-step method used to solve problems: observe natural phenomena and define a problem; formulate a hypothesis; test the hypothesis through experimentation; record and analyze the data; draw a conclusion.

Observation

Gaining information through the senses; data gathered directly from phenomena; involves describing what is seen or heard.

Inference

A conclusion reached after studying the facts or evidence of a case; an explanation that goes beyond what is directly observed.

Problem (Research Problem)

A clear, concise question to be investigated that identifies what you want to find out and guides the IV and DV.

Hypothesis

A tentative answer to the problem; an educated guess that can be tested, often written as If… Then….

Independent Variable (IV)

The variable that is changed or manipulated by the experimenter.

Dependent Variable (DV)

The variable that is measured or observed; the response variable.

Control Variable (CV) / Constant

Variables kept constant throughout the experiment to ensure a fair test.

Experimental Group

The group in which the independent variable is applied and tested.

Control Group

The group in which the independent variable is not applied; used as a baseline for comparison.

Record & Data Analysis

Recording data during an experiment and analyzing results using tables, charts, and graphs to draw conclusions.

Conclusion

Interpretation of the data; states whether the hypothesis was supported; may lead to repeating or modifying the experiment.

Theory

A well-supported explanation of natural phenomena that can be revised with new evidence; not considered an unchangeable truth.

Scientific Law

A statement describing patterns consistently observed in nature; treated as natural truth but may be revised with new information.

Qualitative Data

Data gathered through senses that describe qualities (descriptions) and are not measured.

Quantitative Data

Data gathered using tools that are expressed as numbers and can be measured.

Significant Figures

Digits in a measurement that carry meaning about precision; the last digit is typically uncertain.

Rule 1 – All nonzero digits are significant

Every digit from 1 to 9 counts as significant.

Rule 2 – Zeros between nonzero digits are significant

Zeros between nonzero digits are counted as significant.

Rule 3 – Leading zeros are not significant

Zeros to the left of the first nonzero digit do not count as significant.

Rule 4 – Trailing zeros with a decimal point are significant

Trailing zeros are significant if the number contains a decimal point.

Rule 5 – Trailing zeros without a decimal point are ambiguous

Zeros at the end before an omitted decimal point may not be significant.

Rounding to Significant Figures

Process of adjusting a number to reflect the appropriate number of significant figures.

Rounding to Decimal Places

Rounding based on digits to the right of the decimal; determine which digit to drop.

Addition/Subtraction rounding rule

In sums, the final result should have the same number of decimal places as the term with the least decimal places.

Multiplication/Division rounding rule

The final result should have as many significant figures as the operand with the fewest significant figures.

Accuracy

Closeness of a measurement to the true value.

Precision

Consistency or repeatability of measurements; can be high even if accuracy is low.