1	Measurement & Hypotheses Measurement is at the core of science. Agreeing on how ideas and outcomes can be measured and evaluated is crucial to testing hypotheses with experiments.
2	Reading Assignment In addition to the parts of chapter 1 that describe hypothesis testing and other parts of the scientific method, read appendix A1 and learn the units of the metric system, if you do not already know them.
3	Measurement and Hypotheses Observations (not authority of books or human institutions) are the ultimate source (=authority) of scientific knowledge. Causes are inferred when observations can be organized into repeated patterns. The process of generating cause(s) is called induction. A hypothesis is a statement proposing how something works.
4	OBSERVATIONS Scientists believe there is a ‘real world’ accessible in the same way by all individuals. Measurement and counts are something all individuals can agree on. Most scientific observations involve measurement. Instruments are built to improve measurement range and accuracy.
5	Statistics A value calculated from a set of multiple measurements is called a statistic. Common, simple statistics: Mean Median Variance Range (best expressed as a pair of values)
6	TYPES of Observations (of interest to ecologists) Measurement of fundamental attributes: distance, mass, temperature, time. Measurement of rates, e.g. change per unit time, or even per time squared. Measurement of complex attributes, such as energy = g∙m²∙sec^-2. Abundance, counts of individuals, N.
7	MEASUREMENT Humans have devised many different systems of measurement. Scientists need a universal and simple system. The metric system was adopted by scientists. The SI (metric) system is based on powers of ten. Prefixes allow one to write a large range of measurements succinctly. http://en.wikipedia.org/wiki/SI_prefix
8	Distance (=length) Measurement The meter (m) is the basic unit of length and, therefore, area and volume. People are mostly 1.5 to 2.0 m tall. Single-cell organisms such as algae and protozoa usually are smaller than 1 mm (millimeter) and larger than 1 μm (micrometer).
9	Area & Volume Measurement Area is measured in squared units of length, l², volume in cubed units of length, l³= l•l•l. The ‘hectare’ is the measurement used for large areas such as a farm field. One hectare is 10,000 or 10⁴ square meters (m²).
10	Mass Measurement The basic unit of SI mass is the kilogram, kg. Your textbook weighs 3.4 kg. Your weight (units of force) would be different on the moon than it is on earth, but your mass is the same both places. The mass of carbon in CO₂ in the earth’s atmosphere is 778 Petagrams (=778x10¹⁵ g)
11	Volume measurement Liquids ‘fill’ containers so that the air/liquid boundary is level (due to gravity). This property makes it easy to measure volume of a container. The basic unit of liquid volume is the liter, l. One liter is 1000 cm³.
12	Concentration Different compounds can be mixed in a solution. In such situation we usually measure the concentration of the less abundant component in the more abundant component. Molarity Percent PPM = parts per million, 1 ppm =0.0001%
13	Time Measurement The year is between 365 and 366 days. Calendars attempt to keep each day, say 1 May, in the same position about the sun in every year. The ‘second’ is the SI unit of time.
14	Temperature Measurement Temperature is an especially interesting attribute. There is an ‘absolute zero’. The Kelvin (K) scale places zero there, about 273° C below the freezing point of water. We usually use the Celsius scale in which water freezes at 0° and boils at 100°. °C = (°F – 32)*5/9
15	Induction Observations are organized by the mind into patterns. Patterns are repeatable spatial or temporal organizations. The next element of the sequence: 2, 4, 8, 16, ? is 32, as each element is twice the previous one. Using and inferring PATTERN is a basic human attribute not just for scientists.
16	Deduction Sets of hypotheses provide a framework of knowledge which may be called theory or conventional wisdom. From such frameworks, ideas or hypotheses are derived (= deduced) using reasoning, logic and inspiration. Deduction makes specific predictions using general rules (framework of knowledge).
17	HYPOTHESIS A hypothesis is a statement about what one believes to be true and that can be evaluated by new observations. A hypothesis (statement) can be useful even when it is replaced by a new hypothesis in the future (= proved at least not to have been complete). e.g., Linnaeus hypothesized that the most fundamental separation of living organisms was between plants and animals.
18	EXPERIMENTAL Design Experiments devise situations in which ideas or hypotheses may be evaluated by observations. Manipulated conditions, e.g. a new drug being evaluated, are called ‘treatments’. A good experiment has a ‘control’ which evaluates the ‘no special treatment’ outcome. The control for a new drug is called a ‘placebo’. A placebo creates the illusion that a drug is being taken when no drug is in the ‘pill’.
19	Populations and Probabilities Treatments may change the probabilities of outcomes for members of a population. Both outcomes, cancer & no cancer, occur in the control and other treatments. Statistical analysis of outcomes tell whether or not the probabilities of specific outcomes differ according to treatments.
20	PROBLEM Express the following values in units of meters using exponential notation. A. 0.012 mm B. 567,000 km C. 0.00000098 m D. 5’ 9” Convert 50° F to Celsius.
21	Vocabulary Celsius scale Control Conventional wisdom Experimental design Hypothesis Observation Mean Median Measurement Treatment (group)