Campaign parameters

The parameters described in this reference section determine the interventions used as part of a campaign to control the spread of a disease and the outbreak of the disease itself. Interventions are configured in the campaign file. They are enabled in the configuration file by setting the parameter, Enable_Interventions, to 1. The configuration file also indicates the name of the campaign file.

Warning

The Outbreak must be the last event in the campaign file or none of the interventions will take place.

EMOD supports a variety of supported campaign interventions. It is worth noting that each intervention contains multiple parameters used to configure that specific event. For example, the distribution of bednets behaves differently in the model than does the use of larvicides. It is therefore important to ensure that interventions are configured correctly and applied to the appropriate level target (individual versus node).

This framework enables rigorous testing of possible control strategies to determine which events or combination of events will best aid in the elimination of disease for specific geographic locations.

Like the configuration file, the campaign file is a JavaScript Object Notation (JSON) formatted file. For information on JSON, see EMOD parameter reference. However, the configuration file is mostly a flat list of JSON key-value pairs while the campaign file is structured as an array of campaign events that contain many nested JSON objects. For more information on how to set up the elements in a campaign file, see Create a campaign file.

Warning

Parameters are case-sensitive. For Boolean parameters, set to 1 for true or 0 for false.

The tables below contain only parameters available when using the HIV simulation type.

Events array

The campaign file contains an Events array with one or more CampaignEvent elements and a Use_Defaults parameter. If Use_Defaults is set to 1, the simulation will use the default values for required parameters that are not configured in the campaign file. If it is set to 0, you must configure all required parameters.

{
    "Events": [{
        "Event_Name": "Campaign Event 1",
        "class": "CampaignEvent"
    }, {
        "Event_Name": "Campaign Event 2",
        "class": "CampaignEvent"
    }],
    "Use_Defaults": 1
}

Campaign event

To distribute an intervention, you must configure a campaign event, an event coordinator, and the intervention. The campaign event configures when the event occurs (Start_Day) and where it is distributed (Nodeset_Config). The event coordinator is a nested JSON object in Event_Coordinator_Config. For more information on how to structure this file, see Create a campaign file.

{
    "Event_Name": "Campaign Event Example",
    "class": "CampaignEvent",
    "Start_Day": 1,
    "Nodeset_Config": {
    },
    "Event_Coordinator_Config": {
    }
}

Parameter	Data type	Minimum	Maximum	Default	Description	Example
Event_Coordinator_Config	EventCoordinator	0	3.40E+38	1	The configuration of the EventCoordinator to be instantiated.
Nodeset_Config	NodeSet	0	3.40E+38	1	The NodeSet describing the nodes covered by the event.
Start_Day	float	0	3.40E+38	1	Day of the simulation to activate the event’s event coordinator.

Event coordinators

The Event_Coordinator_Config configures who can receive the intervention (for example, Target_Demographic and Demographic_Coverage) and which intervention is distributed. The intervention is a nested JSON object in Intervention_Config.

{
    "Event_Coordinator_Config": {
        "class": "The event coordinator that will be used.",
        "Target_Demographic": "Everyone",
        "Demographic_Coverage": 0.0005,
        "Intervention_Config": {}
    }
}

Parameter	Data type	Minimum	Maximum	Default	Description	Example
Demographic_Coverage	float	0	1	1	Fraction of individuals in the target demographic that will receive this intervention.
Intervention_Config	Intervention	0	3.40E+38	3.40E+38	The nested json of the actual intervention to be distributed by this event coordinator.
Number_Repetitions	integer	-1	1000	-1	Number of times intervention given, used with tsteps_between_reps.
Property_Restrictions	Dynamic String Set	NA	NA	[]	Fraction of individuals in the target demographic that will receive this intervention.
Property_Restrictions_Within_Node	PropertyRestrictions	NA	NA	Everyone	Fraction of individuals in the target demographic that will receive this intervention.
Target_Age_Max	float	0	3.40E+38	3.40E+38	Upper end of age targeted for intervention, in years.
Target_Age_Min	float	0	3.40E+38	0	Lower end of age targeted for intervention, in years.
Target_Demographic	enum	NA	NA	Everyone	The demographic group (from a list of possibles) targeted by this intervention (e.g., Infants).
Target_Gender	enum	NA	NA	All	Specify the gender restriction for the intervention. Defaults to All.
Target_Residents_Only	boolean	0	1	0	If true, only distribute the intervention to those that claim the node as their residence - i.e. started in the node
Timesteps_Between_Repetitions	integer	-1	10000	-1	Repetition interval.

NodeSet_Config

There are three configuration options: NodeSetAll, NodeSetNodeList and NodeSetPolygon.

NodeSetAll

If you are running a simulation that is in a single location (node) or you want the intervention to be distributed in all of the nodes, use NodeSetAll.

{
    "Nodeset_Config": "NodeSetAll"
}

NodeSetNodeList

The intervention is distributed to nodes in the intervention list.

Parameter	Data type	Minimum	Maximum	Default	Description	Example
Node_List	NodeListConfig	NA	NA	SHAPE	Comma-separated list of node IDs.

NodeSetPolygon

The intervention is distributed in nodes within the specified polygon.

Parameter	Data type	Minimum	Maximum	Default	Description	Example
Polygon_Format	enum	NA	NA	SHAPE	Right now just SHAPE.
Vertices	string	NA	NA	SHAPE	Comma-separated list of polygon points.

Interventions

BirthTriggeredIv

Parameter	Data type	Minimum	Maximum	Default	Description	Example
Actual_IndividualIntervention_Config	IndividualIntervention	0	1	0	The configuration of the actual individual-based intervention sought. Selects a class for the intervention and configures the parameters specific for that intervention class.
Demographic_Coverage	float	0	1	1	Fraction of individuals in the target demographic that will receive this intervention.
Duration	float	-1	3.40E+38	-1	The number of days to continue this intervention.
Intervention_Name	string	-1	1	0	The optional name used to refer to this intervention as a means to differentiate it from others that use the same class.
Property_Restrictions	Dynamic String Set	NA	NA	[]	Fraction of individuals in the target demographic that will receive this intervention.
Property_Restrictions_Within_Node	PropertyRestrictions	NA	NA	Everyone	Fraction of individuals in the target demographic that will receive this intervention.
Target_Age_Max	float	0	3.40E+38	3.40E+38	Upper end of age targeted for intervention, in years.
Target_Age_Min	float	0	3.40E+38	0	Lower end of age targeted for intervention, in years.
Target_Demographic	enum	NA	NA	Everyone	The demographic group (from a list of possibles) targeted by this intervention (e.g., Infants).
Target_Gender	enum	NA	NA	All	Specify the gender restriction for the intervention. Defaults to All.
Target_Residents_Only	boolean	0	1	0	If true, only distribute the intervention to those that claim the node as their residence - i.e. started in the node

BroadcastEvent

Parameter	Data type	Minimum	Maximum	Default	Description	Example
Broadcast_Event	Constrained String	0	1	0	The event that should occur at the end of the delay period.
Dont_Allow_Duplicates	boolean	0	1	0	If an individual’s container has an intervention, set to 1 to prevent them from receiving another copy of the intervention. Supported by all intervention types.
Intervention_Name	string	0	1	0	The optional name used to refer to this intervention as a means to differentiate it from others that use the same class.

DelayedIntervention

Parameter	Data type	Minimum	Maximum	Default	Description	Example
Actual_IndividualIntervention_Configs	IndividualIntervention	0	3.40E+38	6	Array of nested interventions to be distributed at end of delay period to covered fraction.
Coverage	float	0	1	1	Fraction of individuals receiving delayed distribution of configured interventions.
Delay_Distribution	enum	NA	NA	NOT_INITIALIZED	Distribution of duration of delay period. Supported values are: FIXED_DURATION UNIFORM_DURATION GAUSSIAN_DURATION EXPONENTIAL_DURATION.
Delay_Period	float	0	3.40E+38	6	If a FIXED_DURATION is specified as the Delay_Distribution, add this parameter Delay_Period to directly specify the time delay (in number of days). If EXPONENTIAL_DURATION is specified as the Delay_Distribution, Delay_Period, represents the exponential rate that describes the distribution of the time delay (in units of 1/days).
Delay_Period_Max	float	0.6	3.40E+38	0	If a UNIFORM_DURATION is specified as the Delay_Distribution, add this parameter Delay_Period_Max to directly specify the maximum time delay (in number of days).
Delay_Period_Mean	float	0	3.40E+38	6	If a GAUSSIAN_DURATION is specified as the Delay_Distribution, add this parameter Delay_Period_Mean to directly specify the mean time delay (in number of days).
Delay_Period_Min	float	0	3.40E+38	0	If a UNIFORM_DURATION is specified as the Delay_Distribution, add this parameter Delay_Period_Min to directly specify the minimum time delay (in number of days).
Delay_Period_Std_Dev	float	0	3.40E+38	1	If a GAUSSIAN_DURATION is specified as the Delay_Distribution, add this parameter Delay_Period_Std_Dev to specify the standard deviation describing the Gaussian distribution (in number of days).
Dont_Allow_Duplicates	boolean	0	1	0	If an individual’s container has an intervention, set to 1 to prevent them from receiving another copy of the intervention. Supported by all intervention types.
Intervention_Name	string	0	1	0	The optional name used to refer to this intervention as a means to differentiate it from others that use the same class.

HealthSeekingBehaviorUpdateable

Parameter	Data type	Minimum	Maximum	Default	Description	Example
Actual_IndividualIntervention_Config	IndividualIntervention	0	1	1	The configuration of an actual intervention sought. Selects a class for the intervention and configures the parameters specific for that intervention class.
Actual_IndividualIntervention_Event	Constrained String	1900	2200	2000	The event of an actual intervention sought. Selects a class for the intervention and configures the parameters specific for that intervention class.
Dont_Allow_Duplicates	boolean	0	1	0	If an individual’s container has an intervention, set to 1 to prevent them from receiving another copy of the intervention. Supported by all intervention types.
Event_Or_Config	enum	NA	NA	Config	Specifies whether the current intervention distributes a nested intervention (the Config option) or an event will be broadcast which may trigger other interventions in the campaign file (the Event option). See event list.
Intervention_Name	string	1900	2200	2000	The optional name used to refer to this intervention as a means to differentiate it from others that use the same class.
Single_Use	boolean	0	1	1	One-time, or persistent?
Tendency	float	0	1	1	The probability of seeking healthcare.

IVCalendar

Parameter	Data type	Minimum	Maximum	Default	Description	Example
Actual_IndividualIntervention_Configs	IndividualIntervention	0	1	0	An array of interventions distributed as specified in the calendar. Selects a class for the intervention and configures the parameters specific for that intervention class.
Calendar	CalendarIV	0	1	0	An array of ages days and probability of receiving an intervention.
Dont_Allow_Duplicates	boolean	0	1	0	If an individual’s container has an intervention, set to 1 to prevent them from receiving another copy of the intervention. Supported by all intervention types.
Dropout	boolean	0	1	0	If an intervention in the series is missed, all subsequent interventions are also missed. If false (0), all calendar dates/doses are applied independently of each other. If true (1), a missed dose (by applying the probability) will result in no further doses, that is, a miss means you have dropped out altogether.
Intervention_Name	string	0	1	0	The optional name used to refer to this intervention as a means to differentiate it from others that use the same class.

MultiInterventionDistributor

Parameter	Data type	Minimum	Maximum	Default	Description	Example
Dont_Allow_Duplicates	boolean	0	1	0	If an individual’s container has an intervention, set to 1 to prevent them from receiving another copy of the intervention. Supported by all intervention types.
Intervention_List	IndividualIntervention	0	1	0	The array of nested JSON parameters for the interventions to be distributed by this intervention.
Intervention_Name	string	0	1	0	The optional name used to refer to this intervention as a means to differentiate it from others that use the same class.

NodeLevelHealthTriggeredIV

Parameter	Data type	Minimum	Maximum	Default	Description	Example
Actual_IndividualIntervention_Config	IndividualIntervention	-1	3.40E+38	-1	The configuration of the actual individual-based intervention sought. Selects a class for the intervention and configures the parameters specific for that intervention class.
Actual_NodeIntervention_Config	NodeIntervention	NA	NA	[]	The configuration of the actual node-level intervention sought. Selects a class for the intervention and configures the parameters specific for that intervention class.
Blackout_Event_Trigger	Constrained String	0	1	0	The event to broadcast if an intervention cannot be distributed due to the Blackout_Period.
Blackout_Period	float	0	3.40E+38	0	After the initial intervention distribution, the time, in days, to wait before distributing the intervention again. If it cannot distribute due to the blackout period, it will broadcast the user-defined Blackout_Event_Trigger.
Demographic_Coverage	float	0	1	1	Fraction of individuals in the target demographic that will receive this intervention.
Duration	float	-1	3.40E+38	-1	The number of days to continue this intervention.
Intervention_Name	string	0	1	0	The optional name used to refer to this intervention as a means to differentiate it from others that use the same class.
Property_Restrictions	Dynamic String Set	NA	NA	[]	Fraction of individuals in the target demographic that will receive this intervention.
Property_Restrictions_Within_Node	PropertyRestrictions	0	3.40E+38	3.40E+38	Fraction of individuals in the target demographic that will receive this intervention.
Target_Age_Max	float	0	3.40E+38	3.40E+38	Upper end of age targeted for intervention, in years.
Target_Age_Min	float	0	3.40E+38	0	Lower end of age targeted for intervention, in years.
Target_Demographic	enum	NA	NA	Everyone	The demographic group (from a list of possibles) targeted by this intervention (e.g., Infants).
Target_Gender	enum	NA	NA	All	Specify the gender restriction for the intervention. Defaults to All.
Target_Residents_Only	boolean	0	1	0	If true, only distribute the intervention to those that claim the node as their residence - i.e. started in the node
Trigger_Condition	Constrained String	NA	NA	[]	The condition for triggering a health seeking intervention.
Trigger_Condition_List	Vector String	NA	NA	[]	Included if Trigger_Condition is set to ‘TriggerList’. A list (JSON array) of triggers (strings) drawn from config.json ‘Listed_Events’ or from built-in events.
Trigger_Condition_String	Constrained String	0	1	0	Included if Trigger_Condition is set to ‘TriggerString’. Normally Trigger_Condition must specify an event from the built-in list of pre-defined events or triggers from the IndividualEventTriggerType enum. Trigger_Condition_String can be any string provided it is listed in the config.json’s Listed_Events array.

Outbreak

Parameter	Data type	Minimum	Maximum	Default	Description	Example
Antigen	integer	0	10	0	The antigenic ID of the outbreak infection.
Genome	integer	-1	16777200	0	The genetic ID of the outbreak infection.
Import_Age	float	0	43800	365	Age (in days) of infected import cases
Incubation_Period_Override	boolean	0	1	0	0 = outbreak will bypass incubation, 1 = outbreak infection will start from beginning.
Intervention_Name	string	0	1	0	The optional name used to refer to this intervention as a means to differentiate it from others that use the same class.
Number_Cases_Per_Node	integer	0	2147480000	1	Number of new cases of Outbreak to import (per node). This will increase population. There is no control over demographics of these individuals.

OutbreakIndividual

Parameter	Data type	Minimum	Maximum	Default	Description	Example
Antigen	integer	0	10	0	The antigenic ID of the outbreak infection.
Dont_Allow_Duplicates	boolean	0	1	0	If an individual’s container has an intervention, set to 1 to prevent them from receiving another copy of the intervention. Supported by all intervention types.
Genome	integer	-1	16777200	0	The genetic ID of the outbreak infection.
Incubation_Period_Override	boolean	0	1	0	0 = outbreak will bypass incubation, 1 = outbreak infection will start from beginning.
Intervention_Name	string	NA	NA	OFF	The optional name used to refer to this intervention as a means to differentiate it from others that use the same class.

PMTCT

Parameter	Data type	Minimum	Maximum	Default	Description	Example
Dont_Allow_Duplicates	boolean	0	1	0	If an individual’s container has an intervention, set to 1 to prevent them from receiving another copy of the intervention. Supported by all intervention types.
Efficacy	float	0	1	0.5	Represents the efficacy of a PMTCT intervention, defined as the rate ratio of MTCT between women receiving the intervention and women not receiving the intervention. A setting of 1 is equivalent to 100% blocking efficacy, and 0 reverts to the default probability of transmission, configured through the config.json parameter Maternal_Transmission_Probability.
Intervention_Name	string	0	3.40E+38	6	The optional name used to refer to this intervention as a means to differentiate it from others that use the same class.

PropertyValueChanger

Parameter	Data type	Minimum	Maximum	Default	Description	Example
Daily_Probability	float	0	1	1	The probability per day that an individual will move to the Target_Property_Value.
Dont_Allow_Duplicates	boolean	0	1	0	If an individual’s container has an intervention, set to 1 to prevent them from receiving another copy of the intervention. Supported by all intervention types.
Intervention_Name	string	NA	NA	Config	The optional name used to refer to this intervention as a means to differentiate it from others that use the same class.
Maximum_Duration	float	-1	3.40E+38	3.40E+38	Maximum duration of ‘delayed-release’ property change, in days.
Revert	float	0	10000	0	Reversion rate, or the number of days until reversion, or a 2 if reversion is allowed.
Target_Property_Key	Constrained String	0	10000	0	The name of the EMOD-defined property of the group.
Target_Property_Value	Constrained String	0	10000	0	The value of the user-defined group where the individuals will be transitioned.

SimpleDiagnostic

Parameter	Data type	Minimum	Maximum	Default	Description	Example
Base_Sensitivity	float	0	1	1	The sensitivity of the diagnostic. This sets the proportion of the time that individuals with the condition being tested receive a positive diagnostic test. When set to 1, the diagnostic always accurately reflects the condition. When set to zero, then individuals who have the condition always receive a false-negative diagnostic test.
Base_Specificity	float	0	1	1	The specificity of the diagnostic. This sets the proportion of the time that individuals without the condition being tested receive a negative diagnostic test. When set to 1, the diagnostic always accurately reflects the lack of having the condition. When set to zero, then individuals who do not have the condition always receive a false-positive diagnostic test.
Cost_To_Consumer	float	0	3.40E+38	1	The unit ‘cost’ assigned to the intervention. Setting Cost_To_Consumer to zero for all other interventions, and to a non-zero amount for one intervention, provides a convenient way to track the number of times the intervention has been applied in a simulation.
Days_To_Diagnosis	float	0	3.40E+38	0	The number of days from test until diagnosis.
Dont_Allow_Duplicates	boolean	0	1	0	If an individual’s container has an intervention, set to 1 to prevent them from receiving another copy of the intervention. Supported by all intervention types.
Event_Or_Config	enum	NA	NA	Config	Specifies whether the current intervention distributes a nested intervention (the Config option) or an event will be broadcast which may trigger other interventions in the campaign file (the Event option). See event list.
Intervention_Name	string	0	1	1	The optional name used to refer to this intervention as a means to differentiate it from others that use the same class.
Positive_Diagnosis_Config	IndividualIntervention	0	1	0	The intervention distributed to individuals if they test positive. This is only valid if Event_Or_Config is set to ‘Config’.
Positive_Diagnosis_Event	Constrained String	0	3.40E+38	0	The next health care event that occurs for individuals who test negative. This is only valid if Event_Or_Config is set to ‘Event’.
Treatment_Fraction	float	0	1	1	The fraction of positive diagnoses that are treated.

SimpleHealthSeekingBehavior

Parameter	Data type	Minimum	Maximum	Default	Description	Example
Actual_IndividualIntervention_Config	IndividualIntervention	0	1	1	The configuration of an actual intervention sought. Selects a class for the intervention and configures the parameters specific for that intervention class.
Actual_IndividualIntervention_Event	Constrained String	0	999999	10	The event of an actual intervention sought. Selects a class for the intervention and configures the parameters specific for that intervention class.
Dont_Allow_Duplicates	boolean	0	1	0	If an individual’s container has an intervention, set to 1 to prevent them from receiving another copy of the intervention. Supported by all intervention types.
Event_Or_Config	enum	NA	NA	Config	Specifies whether the current intervention distributes a nested intervention (the Config option) or an event will be broadcast which may trigger other interventions in the campaign file (the Event option). See event list.
Intervention_Name	string	0	999999	10	The optional name used to refer to this intervention as a means to differentiate it from others that use the same class.
Single_Use	boolean	0	1	1	One-time, or persistent?
Tendency	float	0	1	1	The probability of seeking healthcare.

SimpleVaccine

The following example provides the syntax for configuring a SimpleVaccine campaign.

{
    "Events": [
        {
            "Event_Coordinator_Config": {
                "Demographic_Coverage": 0.8,
                "Intervention_Config": {
                    ".Reduced_Acquire": 0.9,
                    "Vaccine_Take": 1,
                    "Vaccine_Type": "AcquisitionBlocking",
                    "Cost_To_Consumer": 10.0,
                    "class": "SimpleVaccine",
                    "Waning_Config": {
                        "Initial_Effect": 0.9,
                        "Box_Duration": 730,
                        "class": "WaningEffectBox"
                    }
                },
                "Target_Demographic": "Everyone",
                "class": "StandardInterventionDistributionEventCoordinator"
            },
            "Nodeset_Config": {
                "class": "NodeSetAll"
            },
            "Start_Day": 1460,
            "class": "CampaignEvent"
        }
    ],
    "Use_Defaults": 1
}

Parameter	Data type	Minimum	Maximum	Default	Description	Example
Cost_To_Consumer	float	0	999999	10	Unit cost per vaccine (unamortized). The unit ‘cost’ assigned to the intervention. Setting Cost_To_Consumer to zero for all other interventions, and to a non-zero amount for one intervention, provides a convenient way to track the number of times the intervention has been applied in a simulation.
Dont_Allow_Duplicates	boolean	0	1	0	If an individual’s container has an intervention, set to 1 to prevent them from receiving another copy of the intervention. Supported by all intervention types.
Intervention_Name	string	0	1	0	The optional name used to refer to this intervention as a means to differentiate it from others that use the same class.
Vaccine_Take	float	0	1	1	This specifies the rate at which delivered vaccines will successfully stimulate an immune response and achieve the desired efficacy. If vaccine_take is set to 0.9, then with a 90 percent chance, the vaccine will start with the specified efficacy, and with a 10 percent chance it will have no efficacy at all.
Vaccine_Type	enum	NA	NA	Generic	Type of vaccine to distribute in a vaccine intervention. Possible values are: - Generic - The vaccine can have all of reduced_transmit, reduced_acquire, and reduced_mortality fields and the vaccine will have both effects. - TransmissionBlocking - Specifies the fraction by which the infectivity of the infected and vaccinated Individual is reduced (reduced_transmit). - AcquisitionBlocking - Specifies the fraction by which the force of infection experienced by the vaccinated Individual is reduced (reduced_acqu
Waning_Config	WaningEffect	0	1	1	The configuration of drug-killing efficacy and waning.

Waning effect

Waning effect parameters are used with interventions such as vaccines, drugs, and bednets. It has six different classes. Each class specifies a different waning effect and uses a different combination of the waning effect parameters.

The waning effect parameters are a nested JSON object and can be configured using several different parameters such as Killing_Config, Waning_Config, Blocking_Config, and Mortality_Config. The following example uses Killing_Config. See the specific intervention sections for the supported parameters.

{
    "Intervention_Config": {
        "class": "Ivermectin",
        "Cost_To_Consumer": 1,
        "Killing_Config": {
            "class": "WaningEffectBox",
            "Box_Duration": 3,
            "Initial_Effect": 1
        }
    }
}

WaningEffectBox class

Parameter	Data type	Minimum	Maximum	Default	Description	Example
Box_Duration	float	0	100000	100	Box duration of effect in days.
Initial_Effect	float	0	1	1	Initial strength of effect.

WaningEffectBoxExponential class

Parameter	Data type	Minimum	Maximum	Default	Description	Example
Box_Duration	float	0	100000	100	Box duration of effect in days.
Decay_Time_Constant	float	0	100000	100	Exponential decay length in days.
Initial_Effect	float	0	1	1	Initial strength of effect.

WaningEffectConstant class

Parameter	Data type	Minimum	Maximum	Default	Description	Example
Initial_Effect	float	0	1	1	Initial strength of effect.

WaningEffectExponential class

Parameter	Data type	Minimum	Maximum	Default	Description	Example
Decay_Time_Constant	float	0	100000	100	Exponential decay length in days.
Initial_Effect	float	0	1	1	Initial strength of effect.

WaningEffectLinear class

Parameter	Data type	Minimum	Maximum	Default	Description	Example
Expire_At_Durability_Map_End	boolean	0	1	0	Set to 1 to let the intervention expire when the end of the map is reached.
Initial_Effect	float	0	1	1	Initial strength of effect.

WaningEffectPiecewise class

Parameter	Data type	Minimum	Maximum	Default	Description	Example
Expire_At_Durability_Map_End	boolean	0	1	0	Set to 1 to let the intervention expire when the end of the map is reached.
Initial_Effect	float	0	1	1	Initial strength of effect.