GED Science common mistakes
GED Science · Understand the traps and how to avoid them.
The candidate confuses correlation with causation or misreads a study's design, concluding that an observed association in an experiment or observational study proves the claimed cause.
Headlines and everyday reasoning routinely treat linked variables as cause and effect, and candidates skim the study description without checking for a control group, random assignment, or confounding variables.
What to do instead
For every study question, identify three things first: who or what was studied, whether assignment was random, and what was measured. If there was no controlled manipulation, the finding supports association only. Practice by rewriting flawed conclusions as cautious claims ('is associated with' rather than 'causes').
On science items involving a diagram, data table, or experimental setup, the candidate skips the setup description and answers from the question stem alone, missing the controlled variable or the direction of a trend.
Candidates treat the descriptive paragraph as background and jump to the question, but on this exam the setup usually contains the information needed to distinguish the correct choice from a plausible distractor.
What to do instead
Read the setup once to identify the independent variable, dependent variable, and constants, jotting them in a three-column note. Then check each answer choice against that note, eliminating any choice that contradicts a stated condition or reverses the observed trend.
Chooses an answer from personal experience or general memory instead of from the data in the table, graph, or passage.
HiSET science items often use unfamiliar contexts (a rare frog, a local water table, a specific alloy), so memory offers nothing and candidates fall back on intuition.
What to do instead
Before reading the choices, write one sentence: 'The data show that when X increases, Y ___.' Then eliminate any choice that contradicts that sentence.
Miscounts the axis scale-treats each gridline as one unit when it is 5 or 10-or reads a line's height instead of its slope.
Under time pressure candidates glance at the overall shape and skip the axis labels and units.
What to do instead
Say the axis title and unit silently, then read two explicit points off the axis and compute the change between them.
Mixes up the independent and dependent variable, or labels the control group as the experimental group.
The terms are abstract and are often only implied in the experiment description rather than named.
What to do instead
Write down: IV = what the scientist changed; DV = what was measured; control = the group with no treatment or the baseline condition.
Assumes a dominant allele is the most common allele in a population.
'Dominant' sounds like 'prevalent' in ordinary English, so the two ideas get merged.
What to do instead
Dominance describes expression in a heterozygote; allele frequency is a separate quantity and a recessive allele can be the most common one.
Says energy cycles through a food web the way matter does.
Matter cycles (carbon, nitrogen, water), and candidates transfer that pattern to energy.
What to do instead
Energy enters as sunlight and leaves as heat at every trophic level; only matter cycles. Trace arrows as one-way for energy.
Attributes the seasons to Earth's changing distance from the Sun.
The orbit is elliptical, so distance seems obviously responsible for warmer summers.
What to do instead
Seasons come from the 23.5° axial tilt changing sunlight angle and day length; Earth–Sun distance varies only about 3% and cannot explain opposite seasons in the two hemispheres.
Reads rock layers as oldest-on-top, or ignores that a fault or intrusion is younger than the layers it cuts.
Everyday stacks (laundry, books) put the newest item on top, so the intuition is reversed.
What to do instead
Use superposition (oldest at the bottom) and cross-cutting relationships (a feature that cuts another is younger than what it cuts).