AICE Marine Practical Skills

Even if a hypothesis is supported, it can be changed in the future if new observations are made

true

Steps to the scientific method

-Observations

-Hypothesis

-Prediction

-Experiment

In an experiment there are _________, ________, ________, and __________ variables

Dependent, independent, control, confounding

The variable that is manipulated

Independent

The variable that is being measured

dependent

Variables that cannot be controlled but must be recorded/measured since they can affect the dependent variable

confounding

How would you control the temperature in an experiment?

using a water bath and use a thermometer to measure it

How would you control the pH in an experiment?

using a buffer

How would you control the oxygen levels in an experiment?

bubble into the solution using air pump

How would you control the carbon dioxide in an experiment?

With a hydrogen carbonate solution that will increase the levels thus controlling them

How would you control the light intensity in an experiment?

by maintaining an equal distance from a light source

What equipment would you use to measure liquids?

A graduated cylinder

If I'm measuring the volume of liquids less than 10cm^3 what equipment should I use to measure?

a syringe or a pipette

What is the meniscus?

The curve int he upper surface of a liquid held in a container

Concave meniscus

curves upwards (when measuring water an most liquids)

Convex meniscus

Curves downwards (measuring Hg)

What type of equipment would you use to measure mass?

a weighting scale or a balance

How many values should I have for my independent variable in an experiment?

At least 5 to be able to see trends in the results

How many readings should I take at each value of the independent variable?

At least three

Anomalous results

individual results that don't fit the pattern of the rest of the data and may cause errors

Do you use anomalous results when calculating mean values?

no

Results should be recorded in a ______ for experiments involving measurements

table

The first column in a table is for the ______

independent variable

In some investigations, data is not recorded instead there are _______

large drawings that are done in pencil using a single unbroken line without any shading

How would you present data and observations made?

using graphs and charts; line graphs, histograms, and bar charts

What type of graph is used to show the relationship between two continuous variables?

Line graph

Line graphs are used to show the relationship between two _______ variables like: _____, ______, ______, ______

continuous; time, depth, temperature, salinity

In a line graph where does the independent and dependent variable go?

X-axis = independent

Y-axis = dependent

What type of chart would I use if I want to show frequency data?

A histogram

Are bars connected in a histogram?

Yes

What type of chart would I use if I want to show the relationship between two variables where only one is continuous?

A bar chart

There are gaps between the bars in a bar chart

true

Why are there gaps in a bar chart?

To show that the data is discontinuous

What are the two types of errors?

Systematic and random

Where do systematic errors come from?

Incorrect readings from equipment and affect all of the results equally making them less accurate

Why are systematic errors difficult to identify?

Because the pattern of results stay the same

When do random errors occur?

When one fails to control a variable; like temperature, light intensity

Steps to identify random errors

-Identify anomalous readings and find out why

-Evaluate procedures

-Evaluate the confidence to make conclusions

How could you improve an experiment?

Have more repeats, control variables, use more precise equipment, and use smaller intervals for the values of the IV

Why is it important to suggest improvements?

It increases the accuracy of the observations made