Timeline Guide
The Timeline tool helps you visualize and analyze how content is distributed over time. This guide explains how to read the timeline, interpret trends, and understand the data.
Understanding the Timeline
The Timeline displays content frequency over time, allowing you to:
- Identify peaks and valleys in content creation
- See trends and patterns across different time periods
- Compare activity levels between years or decades
- Understand the temporal distribution of movements or themes
Reading the Timeline
X-Axis (Time)
The horizontal axis represents time, typically displayed in years or months depending on the selected range. You can zoom in or out to see different time scales.
Y-Axis (Count)
The vertical axis shows the number of items (count) for each time period. Higher bars indicate more content created or documented during that period.
Bars/Points
Each bar or point represents the number of items in that time period. Hovering over a bar shows the exact count and date range.
Interpreting Trends
Peaks
High points in the timeline may indicate:
- Major events or movements during that period
- Increased documentation or archiving activity
- Historical moments of significance
Note: Peaks may also reflect changes in data collection methods, not just actual activity levels.
Valleys
Low points may indicate:
- Periods with less documented activity
- Gaps in data collection or archiving
- Historical periods with limited digital documentation
Trends
Overall upward or downward trends can show the evolution of movements, changes in documentation practices, or shifts in focus over time.
Understanding the Count Field
The "count" represents the number of items in our archive for a given time period. Important considerations:
- Count reflects archive content, not real-world activity: A high count may mean more content was archived, not necessarily that more events occurred.
- Historical bias: Recent periods may have higher counts due to better digital documentation and easier access to sources.
- Collection bias: Counts reflect what we've collected, which may not represent the full scope of historical activity.
- Use for relative comparison: Counts are most useful for comparing relative activity between periods, not absolute numbers.
Time Intervals
The Timeline can display data at different intervals:
- Years: Best for long-term trends and broad overviews
- Months: Useful for identifying seasonal patterns or specific events
- Days: For detailed analysis of short-term events or campaigns
Choose the interval that best matches your research question. Longer time ranges work better with year intervals, while focused studies may benefit from monthly or daily views.
Data Limitations & Bias
When interpreting timeline data, be aware of potential biases:
Recent periods may be overrepresented due to better digital preservation and easier access to contemporary sources.
Our collection reflects available sources and curation decisions, not necessarily the full historical record.
Some movements or events may be better documented than others due to media attention, institutional support, or digital accessibility.
Historical content may have approximate or uncertain dates, which can affect timeline accuracy.
Best Practices
- Use the Timeline to identify patterns, then investigate specific periods with search
- Compare trends across different themes or movements
- Consider historical context when interpreting peaks and valleys
- Combine Timeline analysis with Map and Search tools for comprehensive understanding
- Be aware of data limitations and collection biases
- Use appropriate time intervals for your research question
Example Use Cases
Use Timeline with "climate" filter to see temporal distribution, identify peaks, then search specific date ranges for detailed content.
Compare Timeline views across different media types (video, audio, document) to see how documentation practices evolved.