Week 2 Quiz Flashcards
What is a scientific model a representation of
natural phenomeon process system idea object follows logic based on evidence stimulate discussion
system model
org. way to present a system consists of: structures= system components behaviors= relationships b/w components function
function of a system model
what system does, explains. is emergent property; results from relationships that orig. from the interaction b/w two structures; a system could have many functions that provide unique feature of the system
hypothesis
A hypothesis proposes an explanation for an observed pattern. Hypotheses often attempt to identify or explain the cause of a phenomenon (such as the trend of increasing Simploid sickness). To meet the standards of science, a good hypothesis is both testable via experimentation and falsifiable.
independent variable
In an experiment, an independent variable is a likely causal factor that you manipulate. An experiment can have one or more independent variables. For each, the baseline (i.e. unmanipulated) condition is called a control.
Independent variables are sometimes called treatment variables, because their manipulation comprises the experimental treatment.
how does an independent variable effect an experiment
In an experiment, an independent variable is a likely causal factor that you manipulate. An experiment can have one or more independent variables. For each, the baseline (i.e. unmanipulated) condition is called a control.
Independent variables are sometimes called treatment variables, because their manipulation comprises the experimental treatment.
control group
In an experiment, the control group is the group that has the “baseline” condition of the independent variable, providing a comparison to the experimental group in order to assess the effect of the experimental manipulation.
experimental group
receives the experimental condition of the independent variable. In other words, the experimental group is subjected to the hypothesized causal factor. The experimental group is compared with the control group to determine the effect of manipulating the independent variable.
what two groups does a experiment include?
experiment and control group
what happens if you don’t keep all variables constant?
potentially confounding variables
factors that could interfere with the experiment’s outcome are being held constant; potentially confounding variables have been identified and will be addressed
potentially confounding variables
In an experiment, a potentially confounding variable is an extraneous variable that is held constant so that its influence does not affect the outcome of the experiment and lead researchers to the wrong conclusion.
what variables are defined and will be measured in a reliable way?
dependent variables
dependent variables
In an experiment, a dependent variable is one chosen to measure the experimental outcome. A well-chosen dependent variable is expected to change in a particular way if the hypothesis is true and a particular but different way if the hypothesis is false.
Dependent variables are sometimes called outcome variables, because their values will change in response to the experimental manipulation.
experimental units
divided among experimental groups (and control groups randomly)
experimental unit
An experimental unit is the subject of treatment in an experiment. In biology, experimental units can be cells, individual organisms, populations, or whole communities. But they can be defined in many other ways, such as geographically (e.g., areas of land, bodies of water). Ideally, the experimental unit is chosen to fit the hypothesis being tested; however, logistical constraints often influence the experimenter’s choice.
replication
In an experimental setup, replication generally means that the experimenters have included multiplicity in the experiment, in order to avoid drawing conclusions from a single unusual result.
One very important form of replication involves applying each experimental and control treatment to multiple equivalent groups or samples (i.e., experimental units). Each single unit is called a replicate.
Another form of replication involves making multiple measurements of the dependent variable(s).
Replication can also mean repeating the entire experiment.
water is polar b/c of
polar covalent bond
lone e- pairs
the 2 hydrogen atoms and oxygen atom are connected through…
a polar covalent bond
as a result of shared pairs of valence electrons
whats a function in context of a system model
what the system does/explains; its an emergent property’results from relationships that orig. from the interactions b/w two structures; a system could have many functions that all together provide unique feature of the system
What makes a good experiment
- groups that differ only in hypothesized causal factors. (minimal confounding factors)
- control group differs in one way
- well-matched hypothesis
scope of inference
Scope of inference refers to the degree of generality (or narrowness) afforded an experiment’s conclusion, based on the experimental design. Scope of inference is influenced by the choice of experimental unit and level of replication.
systemic variation
When designing experiments, the chosen independent variables should be systematically varied among treatments (such as tanks of snails). Here, “systematic” implies that you are not simultaneously changing multiple independent variables, a pitfall that would make it impossible to tell which variable affected the experiment’s outcome.
whats the design/execution of an experiment
- record data with appropriate dependent variable
- create systemic variation, with appropriate independent variable, control and experimental groups, and holding constant potentially confounding variables
- create replicates of both control and experimental treatments
the execution of an experiment can create….
replicates of both control and experimental treatments
relate conclusion back to real world issue
