Assessing Data Notes – Class 11 Data Science (844)

Assessing Data Notes for Class 11 Data Science (CBSE) are prepared as per the latest CBSE curriculum. These notes cover stories and facts, trial assessments, and perception of time assessment with easy explanations and activities.

Story vs. Facts

Story	Fact
A story is an account of events or experiences presented by a person.	A fact is something that has happened or continues to happen and is considered true.
A story may give more importance either in favor of or against an idea or event.	A fact is based on truth, not on personal opinions or experiences.
Different people may describe the same event in different ways based on their experiences or opinions.	Facts are examined individually or together to draw a conclusion.

Trial Assessment

• A trial assessment is a set of steps performed to support, reject, or confirm an assumption.
• It is also known as an experiment used to test an idea or assumption.

Concept of Correlation and Causation

• Correlation means two or more variables are related, and a change in one variable is associated with a change in another.
• Correlation does not mean that one variable is the cause of the other.
• Causation means that the occurrence of one event causes the occurrence of another event.

Role of Causation in a Trial Assessment

• Every trial assessment includes a treatment variable (independent variable) and a response variable (dependent variable).
• A trial assessment helps researchers study the cause-and-effect relationship between these variables.
• Based on the results, the researcher determines whether the treatment variable has a causal effect on the response variable.

Trial Assessment Example

• A trial assessment is performed to understand the cause-and-effect relationship.
• Students of a grade are divided into two groups for the experiment.
• The first group does not take practice exams, while the second group takes regular practice exams.
• At the end of the academic year, the annual exam results of both groups are compared to observe the effect of practice exams.

Perception of Time Assessment

• Perception of time assessment refers to a person’s subjective experience of time during an event.
• The perceived duration of an event may vary from person to person and in different situations.
• For example, a water park launch chamber ride lasts about 5 seconds.
• A person experiencing the ride for the first time may estimate that it lasted 10–11 seconds, which is longer than its actual duration.

Activity: Effects of Different Duration of Light on the Growth of Radish Seedlings

• The experiment was conducted to study how different durations of light affect the growth of radish seedlings.
• The seeds were exposed to three treatments: 24 hours of light, 12 hours of light and 12 hours of darkness, and 24 hours of darkness.
• Plastic bags with moist paper towels were used as the growth setup to observe seed germination without disturbing the seeds.
• A total of 120 seeds were used to prepare four growth setups, with 30 seeds placed in each setup.
• The growth setups were kept as identical as possible to ensure a fair comparison between treatments.
• After three days, the length of the germinated seedlings was measured in millimetres (mm).
• Seeds that did not germinate were treated as missing values and recorded as “x”.
• The data included categorical variables (growth bag and treatment) and a quantitative variable (seedling length).
• The mean, median, and standard deviation were calculated to compare the growth of seedlings under different treatments.
• The students analyzed whether the differences in the mean lengths of the treatment groups were significant or occurred by chance.
• The seedling length in the 12-hour light and 12-hour darkness group had a mean that was 6.2 mm greater than the 24-hour light group.
• The observed differences could have been influenced by random chance or factors such as uneven distribution of good seeds, light, or water.
• To test this, the students randomly reshuffled the observations and compared the mean lengths repeatedly.
• The reshuffling process was repeated 200 times using technology.
• In all 200 simulations, the observed difference in mean was never exceeded, showing that the difference was not due to chance alone.
• A similar analysis between the 12-hour light and 12-hour darkness group and the 24-hour darkness group also showed that the difference in mean was not caused by chance alone.